Add a true/false field called “done” to you locations collection.
Create a temporary screen with a custom list made of all locations [max records say 20] where status done is false.
Add a back button.
Add the countdown component to the list element with a 3 second countdown and as action when finished add [update current item concatenated field with unit number+tenant] and [set “done” true].
Link to that screen temporarily from a button somewhere
What will happen is every time you go to that screen the update will trigger for the records shown. If you repeatedly go to that screen it will eventually update all the records. Adjust the timer and the no of records in the list according to your speed of updating an Adalo collection (depends on your location, time of day etc) so you do the maximum in one visit to the screen.