I love Tarantino films; major fan. But I don't think he's capable of nuance or subtext, both of which are heavily used in the franchise. I would also abhor a "hard R" Star Trek film. It would be right up there with the Kelvin films. There's no way in hell the fan base would allow something like that to be canonized. The only alternative I could see is if it involved time travel and all of the "hard R"s were from humans from the past.
Star Trek itself often has nuance that's about as subtle as being hit in the face with a brick. Need I remind everyone about Let That Be Your Last Battlefield, TOS S3E15.