I just left it on, I don't really understand it though. I still fail even trivial skill checks repeatedly with anyone other than Astarion so I'm not actually convinced it does anything at all.
I know there is a kind of philosophy in random dice roll design for software where you slightly skew the distribution of subsequent rolls based on previous ones because it feels more random (rather than getting e.g. 1, 2, 1, 2, which could be 'truly random' but feels like ass), but I don't think that's what karmic dice is doing. I do play really high AC, with Laezel and Shadowheart in full endgame plate plus a buff here or there I think they run 24~27. It is very hard for enemies to hit us and it feels about right. I would be very surprised to learn that karmic dice is benefiting enemies too, because that seems unintended and not in the spirit of how the tooltip is written.
I was pretty light on gold for most of the game because I played a sniper ranger so was spending money on arrows CONSTANTLY. Arrow of Many Targets and the one with smokepowder bomb on the end are especially strong but so expensive. I had to raid the bank to be able to afford the Persistence Armor from Dammon for Shadowheart, even after maxing out his attitude... which it was super weird it took 5k in donations considering you know, I saved his bacon twice and I'm trying to save the world.
What I think could have worked was one or two other major late game items could have also been ported to the House of Hope, and you have to part with one knowing you won't get it back. Like as a signal that you are basically at the end of the game now, you need to pick your final party config and get them as set up as possible and start letting other things go. I went in to the final section with a lot of gear on other people I really wish I'd transferred to my core team.