Neat project! (found this by way of your gbdev totp PR)
There shouldn't be issues with MBC1 and banked calls, but if you have a branch with that reproduces the issue I'm open to taking a look at it. I'd also recommend MBC5 as it has all the benefits of MBC1 without the downsides (some banks unavailable to use, though maybe not an issue in your case due to the small total ROM size)
Neat project! (found this by way of your gbdev totp PR)
There shouldn't be issues with MBC1 and banked calls, but if you have a branch with that reproduces the issue I'm open to taking a look at it. I'd also recommend MBC5 as it has all the benefits of MBC1 without the downsides (some banks unavailable to use, though maybe not an issue in your case due to the small total ROM size)