I didn't know apple supported rooted iphones (I do not keep up with apple). Does apple at least provide a warning about invalidating warranties or whatever?

I mean, they don't officially support it, but you can do it.

Been there, done that. It breaks too many things, prevents OTA updates, and some apps just won't run if they detect you've screwed with iOS. I ended up putting my iPad Pro and iPhone (which I have but only use when I need something they offer exclusively) back on official firmware.