I used it on Classic and peg1 and it was very nice. You have to tweak it a little but compatibility is very good. It lets you use 68k, PowerUp and WarpOS software
@McVenco
You could connect a serial cable and see if there's any debug output.
@keropi
Boot manager? simply choose the partition in the early boot menu. It will boot without problems.
If you have doubts about how to install MOS on your classic write me to jcagigal (at) gmail (point) com and I'll help you. It's pretty easy.
Algor/Romulus is no problem to load MOS/OS4. Simply disable it pressing right or left mouse button. Be sure that you are using a modern bootmodule and a modern luciferin.
@Edpon
you can connect your amiga HDs directly. It won't be a problem. Just take care of priority or pass as argument "bootdevice=YOURMOSPARTITION"