Perform skill internals

Does anyone know exactly what Perform skill does, beyond providing bard song upgrades in combo with bard level?

E.g. are there any actual checks of the skill against monster stats? Is it worthwhile to maximize in say a fighter/RDD build that will take only a few bard levels?

In vanilla, it’s mostly upgrades. Some modules use it for social things as well, but that only applies if you’re playing one of those mods, obviously.

I think it only factors as a pre-requisite for feats and levels. As a skill check it is only used in conversations set by module authors, but unless it is stated so, it bears no relevance. I wouldn’t maximize it unless the module/campaign expressly requires it, and there are extremely few doing so.

Thanks all, this makes sense.