Sameboy is highly accurate, I doubt it has problems with most normal games.
Special hardware like the Robotponkotsu games are hardly emulated by any emulator. But that's irrelevant since the emulator source code is just used as documentation.
GBE+ is supporting a lot of the obscure hardware.
Tamagocchi 3 has a custom MBC with an EEPROM, RTC and a piezoelectric beeper.
None of those games run on the EDGB or the X7 they are on real hardware but the only thing I managed to get was the boarders to use on any game, one of them leads up the developer screen which was the poncots USA version but it then whites out. While the others only load the boarders I made a more comprehensive list here of every game in my finalized EDGB version a few years ago it pretty much covers every special chip game even what attatchment was used on it, image heavy incoming...
Special Mapper Games -
https://imgur.com/3MaJ0ZZSpecial Device Games -
https://imgur.com/6PIekbmMapper Games That Work On EDGB Series Including X7 -
https://imgur.com/keeNmb0Comprehensive Enhanced Color Game List which don't load up a boarder so you can add any other game boarder from any SGB enhanced game that is not listed here (Including the 3 games that lost their enhancements to get the colors back via code) -
https://imgur.com/pyRFS5tYou also forgot the include the Mani 4-in-1 series of official Chinese Game Boy compilations.
Oh Those... I think they unlike the others require not much searching up for compatibility as goomba can run most of them this is based off my supercard SD so its likely a comprehensive list of what games you can play on your GBA on the go! Am not sure what they were originally called as I simplified them just like the rest on my Super Card SD that only had a limited amount of characters for each rom when it used to work but if I provide the file sizes it should hopefully help you...
https://imgur.com/G52gh3pOf course none of those in 1 games work on the EDGB as it just shows the blank Gameboy logo line but the mentioned emulator on any other device runs it also that 1st unplayable game being Daikyuu Montigari actually works on the goomba emulator too if I recall as done a few Pokémon hacks being Blacx (A gen 6 hack), Haiiro (A Gen 3 hack if I recall) and XY Naturia (If I recall) though as my device died a long time ago I cant tell anymore but as they worked on goomba it likely works still on GBA these don't work on EDGB either.