diff --git a/packages/data-models/flowTypes.ts b/packages/data-models/flowTypes.ts
index 8b83153593..300db7fc5e 100644
--- a/packages/data-models/flowTypes.ts
+++ b/packages/data-models/flowTypes.ts
@@ -338,8 +338,10 @@ export namespace FlowTypes {
     _dynamicDependencies?: { [reference: string]: string[] };
     _translatedFields?: { [field: string]: any };
     _evalContext?: { itemContext: any }; // force specific context variables when calculating eval statements (such as loop items)
+    _index?: number; // Added dynamically to some rows, i.e. those in item loops
     __EMPTY?: any; // empty cells (can be removed after pr 679 merged)
   }
+
   export type IDynamicField = { [key: string]: IDynamicField | TemplateRowDynamicEvaluator[] };
 
   type IDynamicPrefix = IAppConfig["DYNAMIC_PREFIXES"][number];
@@ -393,7 +395,6 @@ export namespace FlowTypes {
     "save_to_device",
     "set_field",
     "set_item",
-    "set_item_at_index",
     "set_items",
     "set_local",
     "share",
diff --git a/src/app/shared/components/template/components/data-items/data-items.component.ts b/src/app/shared/components/template/components/data-items/data-items.component.ts
index bc8d9c4821..2cd9808690 100644
--- a/src/app/shared/components/template/components/data-items/data-items.component.ts
+++ b/src/app/shared/components/template/components/data-items/data-items.component.ts
@@ -104,18 +104,15 @@ export class TmplDataItemsComponent extends TemplateBaseComponent implements OnD
       if (r.action_list) {
         r.action_list = r.action_list.map((a) => {
           if (a.action_id === "set_item") {
-            a.args = [this.dataListName, r._evalContext.itemContext.id];
+            const row_ids = Object.values(dataList).map((v) => v.id);
+            const row_id = r._evalContext.itemContext.id;
+            a.args = [this.dataListName, row_ids, row_id];
           }
           if (a.action_id === "set_items") {
             // TODO - add a check for @item refs and replace parameter list with correct values
             // for each individual item (default will be just to pick the first)
             a.args = [this.dataListName, Object.values(dataList).map((v) => v.id)];
           }
-          if (a.action_id === "set_item_at_index") {
-            const row_ids = Object.values(dataList).map((v) => v.id);
-            const currentItemIndex = row_ids.indexOf(r._evalContext.itemContext.id);
-            a.args = a.args.concat([this.dataListName, currentItemIndex, row_ids]);
-          }
           return a;
         });
       }
diff --git a/src/app/shared/components/template/processors/item.ts b/src/app/shared/components/template/processors/item.ts
index 61f8a31718..64990f119f 100644
--- a/src/app/shared/components/template/processors/item.ts
+++ b/src/app/shared/components/template/processors/item.ts
@@ -37,7 +37,7 @@ export class ItemProcessor {
   private generateLoopItemRows(templateRows: FlowTypes.TemplateRow[], items: any[]) {
     const loopItemRows: FlowTypes.TemplateRow[] = [];
     for (const [index, item] of Object.entries(items)) {
-      item._index = index;
+      item._index = Number(index);
       const evalContext = { itemContext: item };
       for (const r of templateRows) {
         const itemRow = this.setRecursiveRowEvalContext(r, evalContext);
diff --git a/src/app/shared/components/template/services/template-variables.service.ts b/src/app/shared/components/template/services/template-variables.service.ts
index 75984760e8..90c41a5fe3 100644
--- a/src/app/shared/components/template/services/template-variables.service.ts
+++ b/src/app/shared/components/template/services/template-variables.service.ts
@@ -126,7 +126,7 @@ export class TemplateVariablesService extends AsyncServiceBase {
    **/
   private shouldEvaluateField(fieldName: keyof FlowTypes.TemplateRow, omitFields: string[] = []) {
     if (omitFields.includes(fieldName)) return false;
-    if (fieldName.startsWith("_")) return false;
+    if (fieldName.startsWith("_") && fieldName !== "_index") return false;
     return true;
   }
 
diff --git a/src/app/shared/services/dynamic-data/dynamic-data.service.ts b/src/app/shared/services/dynamic-data/dynamic-data.service.ts
index 78386e05ea..58a4fa09a8 100644
--- a/src/app/shared/services/dynamic-data/dynamic-data.service.ts
+++ b/src/app/shared/services/dynamic-data/dynamic-data.service.ts
@@ -66,18 +66,35 @@ export class DynamicDataService extends AsyncServiceBase {
   }
   private registerTemplateActionHandlers() {
     this.templateActionRegistry.register({
+      /**
+       * Write properties on the current item (default), or on an explicitly targeted item,
+       * e.g.
+       * click | set_item | completed:true;
+       * click | set_item | id: @item.id, completed:true;
+       * click | set_item | _index: @item._index + 1, completed:true;
+       */
       set_item: async ({ args, params }) => {
-        const [flow_name, row_id] = args;
-        await this.update("data_list", flow_name, row_id, params);
-      },
-      set_item_at_index: async ({ args, params }) => {
-        const [targetIndexString, flow_name, currentItemIndex, row_ids] = args;
-        const targetIndex = this.evaluateItemIndexString(targetIndexString, currentItemIndex);
-        const targetRowId = row_ids[targetIndex];
-        if (targetRowId) {
-          await this.update("data_list", flow_name, targetRowId, params);
+        const [flow_name, row_ids, row_id] = args;
+        const { _index, id, ...writeableProps } = params;
+
+        // Target current row if another target is not explicitly provided
+        let targetRowId = row_id;
+        if (_index) {
+          targetRowId = row_ids[_index];
+        }
+        if (id) {
+          targetRowId = id;
+        }
+
+        if (row_ids.includes(targetRowId)) {
+          await this.update("data_list", flow_name, targetRowId, writeableProps);
         } else {
-          console.warn(`[SET ITEM AT INDEX] - No item at index ${targetIndex}`);
+          if (id) {
+            console.warn(`[SET ITEM] - No item with ID ${id}`);
+          }
+          if (_index !== undefined) {
+            console.warn(`[SET ITEM] - No item at index ${_index}`);
+          }
         }
       },
       set_items: async ({ args, params }) => {