write a batch file that cycles through the folder and stores the name of the file before copying the master and renaming it to the stored value.
Unless things have changed, you can't overwrite Access files in use, so you end up with different versions in use at the same time. Don't overthink it - either just download and open every time, or open db, check version in fe table (or custom db property but table is simpler) and shut down if they don't match, then let them do whatever to replace their fe. The only thing you need to do is make sure the newly deployed fe has the new custom property value or the table has the proper value.
EDIT - Just saw prior post. Yes you can call everyone - pita and useless if they're at a meeting or out of the office for a bit.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.