All the trouble shooting I did to get everything working was back in 2020. At this point I do not remember anything. However, over the weekend when I realized I was having trouble bypassing the insert coin request, I noticed that I had compiled a cheat sheet back when I was trying to get everything working. I noted several things a few of which concerned the arcade roms and I will share those notes with you below.
1. No games can have spaces in their filenames
2. Arcade games cannot be renamed and must be sourced from either the MAME 0.37b5 rom set or FBA v0.2.97.39 rom set.
4. Extensions must be .dat for NES., .bin for Genesis and Sega CD, .zim for Mame, .7z for FBA, .fig for SNES.
8. All files must be stored in a directory (folder) named GAME
9. NES, Sega Genesis, Sega CD, Sega Master, SNES, Neo Geo, Game Gear, Mame 2000 (0.37b5) and FBA games are supported using CUSTOM firmware by rrifonas/rmr_md version 2.8.4.
I think now that I was mistaken when I initially said I was using 2.6. I see that I have version 2.8 on my desktop PC along with 2.6 and earlier versions and it looks like it was accessed/modified/created last. Initially I thought 2.6 had a more recent date than 2.8 now I see that it does not.
I only have 3 arcade ROMS installed. All 3 work. 2 have a .zim extension. 1 has a .7z extension.