

Using default proton makes it so Cutscenes in Mega Man 8 don't play. Proton 6 based versions fix this.
This is only for Mega Man 8. The opening cutscene will work if you downgrade. Played the rest of the game and noticed the cutscenes wouldn't work and brings up a static error screen (assuming you're on 6.3-8) Otherwise every other Proton I used would just skip all the cutscenes.
Mega Man 7 was perfect and the challenges have been perfect. Not tested 9 or 10 yet.
No cut scenes for Mega Man 8
I tried different versions of proton, but couldnt find one that would display MM8's cutscene fine. 6.3.8 didnt work for me, only showed test patterns instead of the videos.
The games work well when using Proton 6.3-8 and FMVs work properly. Using newer Proton builds break FMVs but the games still work well.
FMVs do not load in/play at all when using the default Proton build.
This report was made playing a couple stages through each game and testing/troubleshooting FMVs in Mega Man 8.