You won't have any Premier Elements 15 trouble with the current Sony or Panasonic cameras that shoot 4K. You may have trouble with your computer when editing 4K if it is not relatively "strong". The key word is "may". If you have a relatively fast processor, lots of RAM and a relatively fast HDD it will work well.
FWIW, I've been very happy with Premier Elements and 4K from a Panasonic for a couple years. Premier Elements has a system of using preview files that make editing smooth. Output choices are plenty.
Any specific questions?
Mine ranks 7458. It works OK. Part of it is that I use a speedy SSD (Solid State Drive) for Premier Elements, the project, the 4K source files, preview files and the output files.