mod_list = "modid" parameter for Mob Trigger, analogous to biome_category for Biome Trigger. You can generalize a song for only an array of mobs belonging to a mod, that can be combined with MOB and BOSS labels in resource_name, limiting these only to the mobs that come from that specific mod. It could use lists.

An example: mod_list = "alexsmobs;infernalexp;..."

mob ids can be regexed in 5.4 now