So, the latest improvement fixed the libretro core for android to the level of mame_0.155.
Mushihimesama, Futari and Daifukkatsu (the other games are not affected by the issue) now play without errors if:
- delete game.fs before starting game
- after starting the game, go back to Retroarch gui and "reset".
(I've only tested Mushihimesama, but based on the identical behaviour to mame, all should work fine.) Will test further.
Have a great day guys!