Trex-compatible 6 inch post cap

We have a deck built with Trex components, and some of the end caps for the posts got damaged. Some of the caps were shattered (not shown), and in some cases just the brittle mounting tabs were broken as shown.

The size and style of end cap we had isn’t available any more, but we found similar end caps for a 6 inch post. Problem is that the TREX posts are 5.5 inches, made to slide over 4x4s.

Very simple print to design and print (adapter with square hold-down clamps), made with PETG with plenty of walls and top/bottom layers to keep everything snug.