I oughta mention that the merging of versions on the git is separate from actually pushing translation files. It's not like you need to become totally responsible for the maintenance of, say, TW if you just want to contribute translations. Heck, the maintainers probably wouldn't let a random off the street do too much damage to one of the more notable games. Very few of the translators speak Japanese: most of the translations are done by machine and then fixed by editing, from what I understand, in order not to suck. The git repo's instructions are generally "hey we'll take anyone's help."
If you're interested in contributing, you can try the Discord on the wiki, which probably has a lot of overlap with the 8chan thread but I can't say for sure. Don't blame me if you get banned or laughed out of Dodge if you express interest in NTR or cuckolding content, because that'd probably be what happens. It'd probably be best to not talk about F95zone at all if you want to help; it'd just start problems neither site wants due to preexisting enmity.
The translators seem pretty lenient when it comes to exactly how character dialog is translated as long as you're not inventing things from whole cloth for "real" characters--although even that would probably be fine, since most projects have at least some modifications. Nobody would probably care if you fancied up the procedurally generated character dialog as long as it's not crap. There's interest expressed, of course, in keeping existing Touhou and other characters at least somewhat true to their original characterizations (inasmuch as it's possible to do that in a porn game) due to Waifu Syndrome, but if a person were straight translating what the Japanese devs wrote nobody would fault you. As long as you have a clue and don't start fights, they're probably as approachable as any other imageboard folks... which is pretty faint praise, I know.
At the end of the day, the translation community for these games is so small that more or less any earnest and clueful help would probably be accepted. That's really the reason I keep posting here: the vague hope of drumming up additional workers (without starting a inter-board nuclear war). Even the more developed games have usually no more than one or two folks working on them, and there're probably two dozen projects that nobody is or has been translating. If you really wanted, say, EraMeiQGaiden as a personal project, you could probably convince the git maintainers to do it.
For people who are interested, emuera appears to have some built-in replacement-type translation mechanisms. That's what the CSV files are for, I understand. It's not guaranteed that any game uses them or that anything in any particular game uses them, which is why you'll see untranslated Japanese popping up sometimes for things that are in English everywhere else. Ultimately the .ERB files are what would need to be inspected and changed in order to get the games fully translated. There are other considerations for potential translators, though: for certain games some variable or function names might have Japanese in them, and those may or may not be translated to English. Again, since each game is a separate effort by uncoordinated teams, there's very little standardization except for what must happen in order to keep the translations rolling.
Lastly, whatever else happens do keep in mind that both the Japanese and the translation ends of the equation are 100% volunteer and pretty much completely uncoordinated. If some obscure-ass Touhou has a million lines of dialog it's because some enterprising Japanese fellow with a hard on for her has decided to write up her lines; if Reimu's totally untranslated it's because no English-speaker has enough of a boner for her to decide to do it. Don't run over to the 8chan thread complaining about Chen or someone not having enough dialog and expecting anyone to do anything about it. These /b/-style imageboards are not extremely welcoming: they're kind of a Wild West and you should modulate your expectations accordingly. I feel like I'm lecturing the thread, and I'm not talking to anyone in particular, but I don't want to be responsible for a bunch of folks showing up over there munging up the thread or the git with update requests and "hay when is next update" shitposting. As a personal favor to me, think before you interact.