Love turn-based but would offer a few suggestions

Turn-based play is outstanding.  Adding this play mode as an option separates PoE2 from other RPGs in a uniquely positive way.  Way to go devs, the fact that you'd take the work to introduce this well after release is very impressive.

A few comments, many (all?) of which may have already been mentioned/addressed.  Comments are just my opinion, as of course everyone has a method that they'd prefer.  I'd leave it to the devs to figure out what method would provide correct balance and what is reasonably implementable, of course.

1a) Summary: More granularity in AP allocation is needed. Initiative is good, but not enough of a realistic cost to slow actions and slow characters.  Should be a combination of the two, calculated differently.  Some actions shouldn't require a full turn, or at least not as long as other actions.

1b) One action point doesn't really weight a character's dexterity and speed, but two action points would be woefully overpowered.  Maybe a normalized 10AP per round, where movement counts and actions require multiple action points (a portion of unused AP perhaps carrying over to the next round or spent on better initiative in the next round).  This might weight the cost of reloading and different weapon speeds (say, two-handed weapons vs. a stiletto or dual wielding two weapons with different speed costs).  In addition, spell casting early in your AP usage would finish sooner than spell casting at the end of AP usage. 

2) I like the round-based system as it mirrors old-school D&D as far as I remember it.  Or at least mirrors how my group would play it.

3) Spell casting completing somewhere down the list of future actions is excellent.  I haven't seen a way to highlight *when* spell completion would occur when planning whether or not to cast a spell, but I may have just missed it.  This would be important.  

4) Not sure the effect of interrupts/knockdowns is strong enough.  Or maybe I just haven't paid enough attention to the exact result of such; I've seen this comment many times, so in the least the effect needs to be made more obvious.  Perhaps an animation in the turns chart should happen when a change occurs.

5) It's not entirely clear to me how creating engagement works, but that also may be that I just haven't quite figured it out.  Perhaps there should be a small cost in AP to add additional engagements unless a foe creates engagement on its own.

I may be forgetting something, will update if I remember.  In my opinion, the implementation of some method of point #1 is the most important change.  Again, fantastic job and a big thank-you to the devs.  

-David