"A Group is a collection of Backblaze users. All Groups have billing centrally managed by an administrator and allow administrators to keep track of the Group member’s backup statuses, B2 usage, and any alerts that members may have on their Backblaze accounts. Best of all, Groups bring added functionality to Backblaze at no extra cost."
I have supported FM server here for the past 5.5 years (Versions 10-13, so far). It is OK from a small-scale perspective but like you said above, you don't want to look small-scale, especially since you will almost surely trap yourself. As far as I can tell, FM does not scale well. Our FM guy is a co-owner and taught himself how to create and maintain FM databases and he is pretty good at it. However, I am sure there are things he has done that were taking the long way around with a sort of house of cards effect. I would say that over half of our business relies on the 25 or so databases he has created.
I supported FM for a company, NTG's second MSP customer, actually, for over a decade and it does its job well enough for what it is. But there is no doubt that it's extremely limiting in every possible way. They use it for a three person office that was two people in 2001 when the company started and grew to whopping.... two people over a decade later. During the summers they go up to three people for a few months during their busy season. For a company with zero growth and no high reliability demands (it can be down for a month at times without an issue) it worked fine. But, very limiting and they have had to pay a bit for it over the years and I'm not sure that a spreadsheet would not have been cheaper and easier.
If you learn a language just to do this, Python would be my recommendation. Specifically well suited to learning, good for doing small scripts of this nature and good for list processing like this. It's just a good fit. But yeah, if you know some other language already, definitely go with that.
I dislike any whitespace delineated language.
I do hate that aspect of it, very Fortrany, but it does make readability a clearer priority for the newbies and can have benefits, especially when working in teams of non-full time programmers.