Sorry for being so quiet on this. Some of the browser performance issues folks (and myself) had noticed with my MVT demo gave me pause. I seemed like I was seeing a few new issues related to polygon rendering - perhaps
because of updates to the MapBox GL client, regardless culprit had to be my tiles.
Back when the code was first written there wasn't really a means of validating tile structure other than display in a client. I recently discovered the MapBox vtzero project and have been using it to validate output.
While I'm sure the will be other improvements to be made but I fixed a couple of issues including one with polygons having to start with an outer ring. That seems to have fixed the performance and rendering issues I was seeing - which is cool.
I've not seen other changes to the 7.2 branch other than my recent commits and think it's time to release...