You really shouldn't care about the standard. Enterbrain wants us to do a lot of stupid shit but the cool guys aren't having any of that, nosuh! Here in the backstreets we event our own systems, yeah!
Personally, I found BGMs at 100 to be a little inappropriately loud. Tuning everything down to 80 might just be a beneficial change even if you didn't want something else to be extra noisy; it's not going to kill gameplay if the player has to go up one notch on his volume dial, so don't stress too much about it.