Follow up - the ejection has been a bit better, still erratic just not in my face which is nice. It has allowed me to set a few PR's and do a bit better in competitions than normal - anecdotal and not scientific for the latter of course.
BUT, my G17* did have a sideways stovepipe at this past match. Oh well!
*G17 with HRED and original 336 ejector and original extractor (this combo gave the most reliability up until now, may experiment again with the APEX extractor and 30274)