I appreciate support sharing that a new release is coming out shortly, and as a result patiently await when they are ready. If we harass them about missing dates they won’t give us a heads up next time.
As for the focus on certified, could be a reason for the longer releases and lack of third party support. I recall the old Dynon when they Considered it, now when I ask to get my uavionox to be seen on display I’m told it isn’t possible, I understand the conflict of interest, but it’s also cost prohibitive going with dynon mode s compared to meeting the adsb compliance at a much lower price range. New releases aren’t nearly as exciting as it used to be so 15.4 may add something but I’m not using foreflight so 15.4 probably adds nothing new I can’t wait for.