In my very limited experience with Excel in SP I had to have permissions on the SP server. In other words, I could see it in Windows File Explorer - before I could do any development. Only certain users had use of this particular process and they all had permissions on that server as well so it's my recollection that it would not run for anyone who didn't have those permissions. However, I used Automation to push Access data to the workbook, probably because a workbook could not be modified without "checking it out" first. If anyone was in it, it could not be accessed, thus I never even attempted to link the sheet in Access. Moving sheet data into/out of Access via automation might be your only option. Your code would have to determine if the workbook is checked out, which is an actual property of the workbook IIRC.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.