brliron
commented
2 years ago custom.exe had an English version since th14 (I think ZUN introduced that in the Playism version), and we do suppose them, th18 is the only one we don't support.
I think we just forgot to work on custom.exe when we worked on th18. If you look in base_tsa (https://github.com/thpatch/thcrap-tsa/tree/master/base_tsa), you can see a _custom folder for every Touhou game but Touhou 18.
Probably that's because th18's custom.exe already supports English (for non-Japanese locale)? But we need support for non-English-speaking users too, just like the older games.