Good news for all you 13,2 users out there, it looks like the install via the update wizard went flawlessly again to beta 5.
Same issue reported as with beta 4 with the BT
in that it appears to not be working again - however, this time, unlike with beta 4, my trackpad 2 appears to be working correctly with all features working, including right click (two finger tap) gestures, pinch etc meaning as last time the BT stack just needs a little kick.
Using the same reset as last time from
@RogueB - "sudo kill -9 $(pgrep bluetoothd)" - fixed the issue instantly and off we go with full BT support again including the copy and paste from other devices (handy while writing this post).
So it seems another win for us little guys and big thanks of course to all those insanely clever people above who have all helped to get us this far - long may this continue as I don't want to get rid of my lovely 13.2 iMac just yet.