INES Mapper 241
iNES Mapper 241 appears to be assigned as a "dubious implementation" marker by the FCEU-MM/FCEUX developers for games that might have issues being run as mapper #34 / BNROM. Some of those issues may be due to NINA-001's and BNROM's cohabitation of mapper 34.
This is further complicated by that all of these games appear to only exist in Chinese and so current NES emulator authors have little ability to playtest and document what behavior is needed.
ex. Fan Kong Jing Ying (Unl) (Ch), Edu (As)
Some games may need reads from the $5xxx range to return specific values. (But are they actually iNES Mapper 164?)
This is supported in fceu-mm, fceux, and bizhawk (at least)