TeenageAssassin

Prim+ is an amazing game mode. I'd say the best option would be to add it as a mod, but possibly with special servers (like hardcore, 6 man etc) that have tek ect disabled, so the people who play only for that reason can move there, but everyone else can access the building stuff for official servers. As a pve player I love prim+, however there was never any official pve prim servers, so I had to go to unofficial. I think for pve players all of the building bits would be great, especially if some things could get a reskin, indy forge looking like the prim+ version and the chairs, windmills, smokehouse etc. However, whatever you decide to do, there should be some sort of compensation for those playing prim, like letting them upload their dinos and character, to bring over to the new servers so it's not a start from scratch problem.