D'oh, I knew I forgot to post somewhere, I should have made a topic on it.
Late on Saturday, an issue arose with Gemp's configuration that led to it not starting up after a restart. It took me the better part of a day to track down the exact issue, but Gemp is now up and running.
(And as a silver lining, one of the things I did in despair while trying to fix it was upgrade all the long-outdated packages on the server, so that maintenance is done lol.)