Hey Ian,
Atari ST nowadays is pretty much halted, the last changes were introduced by Diabol so you might want to contact him. However i think he is not currently working with them.
Any help is welcomed so feel free to choose the system / job that you enjoy more, even if Amiga is more active.
The renaming process is quite simple, if you're (re)starting, just try to identify exactly what those unrenamed sets are and why they differ the known ones and follow the TNC (don't use just title, year and publisher if more info is available). After renaming a bunch of them, create a new datfile and submit it to be checked. There is a tool (TDE) that might help you identifying possible renaming (TNC) mistakes.
If you decide to go ahead just pm me so i can give you some additional information.