Sorry I had missed your question on the center caps earlier. Nice work answering your own question
. I too had this question and saw that it was like other good quality wheels I’ve had... just push them from the inside and have your other hand ready to catch it as it pops out. For the valve stems I really wanted to keep that BC Forged metal valve stem look with TPMS. So I found TMPS sensors with black metal stems on eBay. I should be able to unscrew the metal stem that came with the sensor and use the ones from BC Forged. If not, the ones I picked up look pretty damn close to the ones on the wheels minus the end caps (easy swap).