I think Dreamcast should be separated between Emulation and Original Console, related for loading times especially in Original Hardware-Console. In emulation stuff probably no banned emulators should be considered (for now), probably Mame for Arcade emulation would fit 100%, and also probably Flycast and NullDC for Dreamcast emulation will fit. I have done the separation in Dreamcast for Giga Wing 2, between Emulation and Original Hardware.
Well, if u want a different leaderboard you should do a request thru SRC (by requesting a new game option), giving all the info you know, giving all the details needed. Probably it could be part of the Mega Man series, and if it is classic, better. So, it depends if the idea is acceptable or not for a new leaderboard in SRC. Good luck.
Ok... the MM Anniversary Collection leaderboard you can find it here:
It is not possible unfortunately. Play the NES game in a basic mode by using the emulators pointed out in the google document attached.
https://docs.google.com/document/u/0/d/1apP69VDIzUx-iVO_sj5YjTxBAE2ukHPa6kl33AOW9hA/edit?usp=sharing&pli=1 check this out, done for more detailed information involving a lot of stuff for NES speedrunning.