I’m a much smaller stake holder than you, and my vote is dust compared to yours. Lol
But I like to keep my autothreshold at 80%. Like you though, I still find myself manually draining it to around 76% sometimes because once I find really good content even when my vote is already at the threshold, I can’t resist hitting upvote. And my very big problem is that I almost always vote with 100% since my voting power is already small even for a 100% vote.
I don’t have a fix that works either, and I don’t think I can suggest anything you already don’t know. I guess it’s just about discipline of choosing to not curate irrespective of situations once your voting power goes below a certain threshold.
No one can resist hitting "upvote from time to time" it shows that you're actually very active in my opinion. People who aren't active does not need to worry. But well, having a vote slider, whether your state is small still means you get to make tough decisions about who gets your vote and who doesn't. For me I like to keep it above 75% so that my vote weight can still be as solid as ever. Not to worry, no one ever finds a balance for these things.