I suggest an optimisation for step 2 in the article linked:
Change
SELECT(Employees[Employee ID], [Employee ID] = [_THISROW].[Employee ID])
To
LIST([Employee ID])
Since Employee ID is a referenced column. I believe this will prevent having to search your entire table for the fields to act on
2. Create an action. Set Action name to “Get Employees to Update”. Set For a record of this table to the Employees table. Set Do this to “Data: execute an action on a set of rows”. Set Referenced table to the Employees table. Set Referenced Action to “Update Employee Status”. Set Referenced Rows to an expression that returns a list of row keys from the Employees table. The row keys will be used by AppSheet to identify the employees to be updated. For example, to select the employee that has been assigned to the current project, use the expression:
SELECT(Employees[Employee ID], [Employee ID] = [_THISROW].[Employee ID])