In regards to the four gem match bug, I think what you linked to is different. The link shoes the gem moving incorrectly, but it is properly registering if its a 3 or 4 gem match.
I explained in a comment on that thread {FINALLY ON FILM! NOT A BUG (lol) BUT REPORTED] Caught the (a) match-4 bug on video - #4 by Snooj why its happening and how to reproduce it every time. Basically, the game is using flick prediction which while great for mobile phones, is terrible with a mouse.
I would be very surprised if they ever fix it. 6.0 was the time to fix it but they didnt. Core gameplay issues, even if easy to change, require full regression testing. A new expansion like 6.0 is perfect for that.
But… They didnt even test that their shiny new journey miles was correct… So lol at regression testing.
Speaking of miles calculation, how did this make it live? How was this not caught by the devs themselves? QA? Beta testers? During any of the internal demos? How?