On an original hardware setup for BS Fire Emblem, L+R+START+SELECT would return the player to the beginning of the most recent player phase. This effectively works as an early iteration of rewind features in many modern FE games. You could do this to save a unit from dying or to retry when you get rotten luck and need that critical hit. However, on ROMs modified to work outside the Satellaview environment, this would instead operate like a hard reset, sending you to the very beginning of the episode. This has likely influenced perception of BSFE's difficulty for years. These are generally seen as hard maps - and if you insist on not using this feature, they indeed are very much so. It's unfortunate and ironic that it was seemingly unintentionally removed as a consequence of attempts to make BSFE more accessible.

(Scan source: god-bird.net/research/satell… ) Prerelease art/screens of the new characters in BS SimCity VS. the same characters in the ROM dump of BS Simcity Dai-3-wa.