And what is even worse, if you have at least ONE additional custom character in your party, ALL conversation triggers in the world are overwritten by some meaningless "chat between PCs" where everyone state their mind wich can be only picked in one of two options (either entirely refusing the situation, or entirely accepting it), and then, if you pick different choices, the one who triggered it simply states there is no point in talking about it!
This sounds like a hold-over from D:OS where ( in single-player ) you control 2 "Heroes" that have frequent conversations like this. In D:OS this actually had a purpose, because the choices you made in these conversations defined the character of your heroes, and more importantly, gave you in-game stat modifications that affected game systems ( I have no idea if the stat modification also applies in BG3 as I have not used more than 1 custom character ).
It was an interesting experiment, I suppose, but I never found the conversations to be very satisfying, particularly once you had worked out the stat modification metagaming and chose dialog on that basis.
On a more general note, yes, the dialog progressions can be a mess, particularly with Gale. If you make an effort to play the game in random ways rather than following the breadcrumbs, you will get all sorts of weird dialog, most of which is comments that imply you have seen or experienced something that you have not.
If there is an abundance of "flavour" dialog in the game, I don't feel the need to experince it all in every playthrough, but if important dialog
is missed or order-dependency not maintained, then that does imply a weakness in their current system. A recent interview had a developer describing a late-game branching conversation needing 800 ( I think ) decision points from previous game activity. This does not fill me with confidence, given how broken some of the EA dialog seems to be.
