I agree with a very large fraction of what is a large post. So, yeah, agree++, The Old Soul. The only technical detail I would raise is : strictly speaking, there is no surprise round. It's just round 1, where all enemies are surprised ... which in terms of effects and output is the same.

I complained about the same things in my initial feedback on this. But I'm increasingly realising that my fundamental problems with this "in-combat vs out-of-combat timelines" are not what I described.

Some grounds for complaint about the current system is that it allows exploits and utterly ridiculous scenes. Some examples :
  • Some party members, who are very far from the fight, have all the time in the world to come and help their friend, who got in the fight on their own.
  • A Rogue who, really, should have been drawn in the fight due to where she is, has the time to do 3 rounds worth of movement to get in the perfect position and activate buffs before getting in the fight.
  • The out-of-fight Warlock spamming Imps (see JaceEthaniel's post above)

But those are just exploits. Larian loves them. And I can refrain from using them.

So then, what is, to me, the real problem with in-combat vs out-of-combat timelines ?

In short, this system occasionally penalises players and it routinely prevents them from accomplishing simple things they should very much be able to do.

* Ambush (see The Old Soul's post as well). It's a very simple thing. You are in Turn-Based Mode, you want to play all you team's turn before The World or The Combat interrupts you. Currently, The Combat interrupts you and you can rarely finish your ambush properly.
Now, one may argue, "why should players have their ambushes work with 100% success ? After all, this is DnD. Swinging a sword doesn't result in a hit all the time". In my view, when a player has managed to place their team in the right spots, has activated Turn-Based Mode, and is ready to strike, they have already succeeded at the ambush. The "does Ambush succeed ?" question is encapsulated in the Stealth vs Perception checks. If the enemies didn't spot the party, they get ambushed.

* Penalising situation. You are in combat with goblins in the Underground Passage underneath the Grove, the Guardian Statues are outside the Combat-Time-Bubble and they fire at you at an insane rate. Super nice.

* Penalising situation. You have activated Turn-Based Mode to cast Bless and avoid wasting rounds of buff effect, then you have sneaked around enemies. Combat starts, some characters are not drawn in, and by the time one of your character has their combat turn, and you can pause the combat to draw the other characters in, they have lost many rounds of buff effect. Awesome. Here my problem isn't even so much that seeing Gale with 2 rounds left of Bless effect while Shadowheart has 9 rounds left, even though it came from the same spell, is a blatant record of the ridiculous existence of multiple timelines. The problem is that I don't get the full effect for which I paid a full spell slot.