diff --git a/packages/web_ui/src/components/BaseConfigTree.tsx b/packages/web_ui/src/components/BaseConfigTree.tsx
index a17a11dd..00f5962d 100644
--- a/packages/web_ui/src/components/BaseConfigTree.tsx
+++ b/packages/web_ui/src/components/BaseConfigTree.tsx
@@ -9,6 +9,7 @@ import * as lib from "@clusterio/lib";
 import ControlContext from "./ControlContext";
 import { InputComponent, InputComponentProps } from "../BaseWebPlugin";
 import type { Control } from "../util/websocket";
+import { notifyErrorHandler } from "../util/notify";
 
 const { Title } = Typography;
 
@@ -67,8 +68,7 @@ function renderInput(inputComponents: Record<string, InputComponent>, def: lib.F
 type BaseConfigTreeProps = {
 	ConfigClass: typeof lib.ControllerConfig | typeof lib.HostConfig | typeof lib.InstanceConfig;
 	retrieveConfig: () => Promise<lib.ConfigSchema>;
-	setField: (field:string, value:any) => Promise<void>;
-	setProp: (field:string, prop:string, value:any) => Promise<void>;
+	setConfig: (fields: Record<string, string | Record<string, string>>) => Promise<void>;
 	id?: number;
 	onApply?: () => void;
 	available?: boolean;
@@ -157,32 +157,25 @@ export default function BaseConfigTree(props: BaseConfigTreeProps) {
 					loading={applying}
 					onClick={async () => {
 						setApplying(true);
-						for (let field of changedFields) {
-							let value = form.getFieldValue(field);
-							let request;
+						const fields: Record<string, string | Record<string, string>> = {};
+						for (const field of changedFields) {
+							const value = form.getFieldValue(field);
 							if (propsMap.has(field)) {
-								let [fieldName, prop] = propsMap.get(field)!;
-								request = props.setProp(fieldName, prop, value);
+								const [fieldName, prop] = propsMap.get(field)!;
+								const fieldValue = (fields[fieldName] ?? {}) as Record<string, string>;
+								fields[fieldName] = fieldValue;
+								fieldValue[prop] = value ? JSON.parse(value) : undefined;
 
 							} else {
-								request = props.setField(field, value === null ? "" : String(value));
+								fields[field] = value === null ? "" : String(value);
 							}
+						}
 
-							try {
-								await request;
-								setChangedFields(changed => {
-									let newChanged = new Set(changed);
-									newChanged.delete(field);
-									return newChanged;
-								});
-
-							} catch (err: any) {
-								setErrorFields(errors => {
-									let newErrors = new Map(errors);
-									newErrors.set(field, err.message);
-									return newErrors;
-								});
-							}
+						try {
+							await props.setConfig(fields);
+							setChangedFields(new Set());
+						} catch (err: any) {
+							notifyErrorHandler(err.message);
 						}
 
 						await updateConfig();
@@ -325,26 +318,23 @@ function computeTreeData(
 								}
 
 								if (!def.validator) { return; }
-
-								// TODO this needs to use stage and stageProp to avoid deadlocks
-								const staging = config.staging;
-								staging.setProp(fieldName, prop, fieldValue);
+								config.stageProp(fieldName, prop, fieldValue);
 
 								for (const dependsOn of def.dependsOn ?? []) {
 									const dependsOnDef = ConfigClass.fieldDefinitions[dependsOn as any] as typeof def;
 									try {
 										if (propsMap.has(dependsOn)) {
 											const [name, otherProp] = propsMap.get(dependsOn)!;
-											staging.setProp(name, otherProp, JSON.parse(getFieldValue(dependsOn)));
+											config.stageProp(name, otherProp, JSON.parse(getFieldValue(dependsOn)));
 										} else if (dependsOnDef.type !== "object") {
-											staging.set(dependsOn, getFieldValue(dependsOn));
+											config.stage(dependsOn, getFieldValue(dependsOn));
 										}
 									} catch (err) {
 										throw new Error(`Failed to fetch field: ${dependsOn}`);
 									}
 								}
 
-								def.validator(fieldValue, staging);
+								def.validator(fieldValue, config.staging);
 							}})]}
 						>
 							<Input className="json-input" disabled={!canWrite} />
@@ -418,26 +408,23 @@ function computeTreeData(
 					rules={[({getFieldValue}) => ({
 						validator: async (_, fieldValue) => {
 							if (!def.validator) { return; }
-
-							// TODO this needs to use stage and stageProp to avoid deadlocks
-							const staging = config.staging;
-							staging.set(fieldName, fieldValue);
+							config.stage(fieldName, fieldValue);
 
 							for (const dependsOn of def.dependsOn ?? []) {
 								const dependsOnDef = ConfigClass.fieldDefinitions[dependsOn as any] as typeof def;
 								try {
 									if (propsMap.has(dependsOn)) {
 										const [name, prop] = propsMap.get(dependsOn)!;
-										staging.setProp(name, prop, JSON.parse(getFieldValue(dependsOn)));
+										config.stageProp(name, prop, JSON.parse(getFieldValue(dependsOn)));
 									} else if (dependsOnDef.type !== "object") {
-										staging.set(dependsOn, getFieldValue(dependsOn));
+										config.stage(dependsOn, getFieldValue(dependsOn));
 									}
 								} catch (err) {
 									throw new Error(`Failed to fetch field: ${dependsOn}`);
 								}
 							}
 
-							def.validator(fieldValue, staging);
+							def.validator(fieldValue, config.staging);
 						},
 					})]}
 				>
diff --git a/packages/web_ui/src/components/ControllerConfigTree.tsx b/packages/web_ui/src/components/ControllerConfigTree.tsx
index a369fab7..aecd5c03 100644
--- a/packages/web_ui/src/components/ControllerConfigTree.tsx
+++ b/packages/web_ui/src/components/ControllerConfigTree.tsx
@@ -13,30 +13,13 @@ export default function ControllerConfigTree() {
 		return await control.send(new lib.ControllerConfigGetRequest());
 	}
 
-	async function setField(field: string, value: any) {
-		await control.send(new lib.ControllerConfigSetFieldRequest(
-			field,
-			String(value),
-		));
-	}
-
-	async function setProp(field: string, prop: string, value: any) {
-		if (value) {
-			try {
-				value = JSON.parse(value);
-			} catch (err) {
-				return;
-			}
-		} else {
-			value = undefined;
-		}
-		await control.send(new lib.ControllerConfigSetPropRequest(field, prop, value));
+	async function setConfig(fields: Record<string, string | Record<string, string>>) {
+		await control.send(new lib.ControllerConfigSetRequest(fields));
 	}
 
 	return <BaseConfigTree
 		ConfigClass={lib.ControllerConfig}
 		retrieveConfig={retrieveConfig}
-		setField={setField}
-		setProp={setProp}
+		setConfig={setConfig}
 	/>;
 }
diff --git a/packages/web_ui/src/components/HostConfigTree.tsx b/packages/web_ui/src/components/HostConfigTree.tsx
index aef520f0..caf8d4a1 100644
--- a/packages/web_ui/src/components/HostConfigTree.tsx
+++ b/packages/web_ui/src/components/HostConfigTree.tsx
@@ -13,28 +13,14 @@ export default function HostConfigTree(props: { id: number, available: boolean }
 		return await control.sendTo({ hostId: props.id }, new lib.HostConfigGetRequest());
 	}
 
-	async function setField(field: string, value: any) {
-		await control.sendTo({ hostId: props.id }, new lib.HostConfigSetFieldRequest(field, value));
-	}
-
-	async function setProp(field: string, prop: string, value: any) {
-		if (value) {
-			try {
-				value = JSON.parse(value);
-			} catch (err) {
-				return;
-			}
-		} else {
-			value = undefined;
-		}
-		await control.sendTo({ hostId: props.id }, new lib.HostConfigSetPropRequest(field, prop, value));
+	async function setConfig(fields: Record<string, string | Record<string, string>>) {
+		await control.send(new lib.HostConfigSetRequest(fields));
 	}
 
 	return <BaseConfigTree
 		ConfigClass={lib.HostConfig}
 		retrieveConfig={retrieveConfig}
-		setField={setField}
-		setProp={setProp}
+		setConfig={setConfig}
 		id={props.id}
 		available={props.available}
 	/>;
diff --git a/packages/web_ui/src/components/InstanceConfigTree.tsx b/packages/web_ui/src/components/InstanceConfigTree.tsx
index c9a45530..ff028ddd 100644
--- a/packages/web_ui/src/components/InstanceConfigTree.tsx
+++ b/packages/web_ui/src/components/InstanceConfigTree.tsx
@@ -17,28 +17,14 @@ export default function InstanceConfigTree(props: InstanceConfigTreeProps) {
 		return await control.send(new lib.InstanceConfigGetRequest(props.id));
 	}
 
-	async function setField(field: string, value: any) {
-		await control.send(new lib.InstanceConfigSetFieldRequest(props.id, field, value));
-	}
-
-	async function setProp(field: string, prop: string, value: any) {
-		if (value) {
-			try {
-				value = JSON.parse(value);
-			} catch (err) {
-				return;
-			}
-		} else {
-			value = undefined;
-		}
-		await control.send(new lib.InstanceConfigSetPropRequest(props.id, field, prop, value));
+	async function setConfig(fields: Record<string, string | Record<string, string>>) {
+		await control.send(new lib.InstanceConfigSetRequest(props.id, fields));
 	}
 
 	return <BaseConfigTree
 		ConfigClass={lib.InstanceConfig}
 		retrieveConfig={retrieveConfig}
-		setField={setField}
-		setProp={setProp}
+		setConfig={setConfig}
 		id={props.id}
 	/>;
 }