Hello there, misha1350. You might want to apologize for that necro-bump.
To answer your question, the latest versions of MAME have not fully fixed the YMF271 emulation, but it's mostly the FM emulation that is flawed.
The YMF271 emulation had many earlier issues that were fixed years back, such as samples being cut off and music playing at the wrong speed (too fast in Battle Balls, too slow in Desert War, P-47 Aces, and Tetris Plus). However, the emulation (mostly for the FM part) still isn't quite accurate to the real chip.