According to the folks at TFBTV, PWS is still trying to work the bugs out of the UXR. There is a brief discussion at the 9:35 mark of this video:
https://youtu.be/gdQ0SdmsH3c?si=th-eJorf9ZEveKHm
My interest is on hold until it’s been out for a couple of years and it’s proven reliable in at least the 5.56 and .308 configurations.