You can change it at any time i think.

I was playing balanced and changes to tactician two days ago to see how it was. Was expecting to get clobbered, but actually it’s been going fine. The fights are tough, but it sorta quickly pushes you to pay more attention, examine enemies, think about positioning a bit more. The Grymforge fight was way larger than I had expected, and I decided to play it a bit, die and then reload, but I ended up beating it (although poor station did get treated into the lava, and I tested Nere in after him).

Anyway, so far I’m loving tactician, don’t think I need to shift back down. It uses up camp supplies more, both because the cost is 80, and I find that I need to long rest more frequently because I use my character resources up more fully in every engagement. I don’t foresee it becoming a situation where the supplies economy actually starts to become a pressure point, supplies are super prevalent, but it does make make me more “excited” to pick up and store all those wine bottles and mushrooms…

Caveat is you do have to be comfortable getting wiped in engagements, then reloading and trying a different strategy. I’m doing my first playthrough, so most encounters are unknown to me when they start, which means it’s easy to get caught in bad positions, etc.

I say try it if you’re curious—you can switch it back down if you find it frustrating with no downside.