Simply one bug, and one bug only:
When loading into areas, you're kicked out of your menus. It was fixed in D2 vanilla, but broke again in Foresaken.
In D1 it was a major issues. You'd get booted once, twice, three or four times. When it was fixed in D2 there was quite a few people excited about it, but since it has came back(thankfully in a less frustrating way) there has been no mention.
If it's intentional as some people have said, to alert the player they've loaded, then that's fine. Just say so.
Whilst I have your ear though - thanks for taking the time to respond. In D1 I had several issues and reached out on the Bungie Help Forums(as per your official guidelines for support), but never received a response. For awhile I checked back and would browse unanswered posts littered about and it was very disheartening hitting stuff that nobody else has issues with and the people that can help you don't reply.
I guess what I'm getting as is that I'm worried about the customer support side of things, especially since New Light is coming and plenty of new players will be joining our ranks. My support experiences through the course of Destiny have been lackluster, and I don't want other players to hit the same things I do.
That is all. Downvote as you see fit, I'll answer each and every comment directed towards me in a moment and then go back to just browsing Reddit like I used to.
EDIT: Added on to the last two paragraphs.