I recommend playing it through once in early access as an origin character if you don't plan on playing one on release, or a created character once if you plan to play an origin character on release. Also the mechanics are different for this one enough that even with a ton of DOS1 experience, DOS2 has enough new mechanics that it would be a good idea to wrap your head around a couple by trying it once. Then when the game releases you can know what things you did in your first early access playthrough and what you don't want to do because it doesn't work the way you thought it would.
I personally prefer to get surprised with discoveries and that is one of reasons why I did not played much of act 1. Plus I am planing at least two or three playthroughs but personally dont like idea of first play to know "ah this is there, for this key go there" and similar stuff. I just tried game little but somehow kept my patience.... sorta I messed on char creation screen loooots of time
