Need some opinions on where to go from here...

Your best case is to make a list of the things you can do with the engine in the car and check them off 1 by one and then if nothing is resolved, pull the engine and check everything over 1 by one. I personally would look at the rockers, and do another compression test with putting some oil in and seeing what happens, you could have an issue with the rings if everything else is new and working "well"