You didn’t like the resistor solution as it only cured the symptoms, not the cause, using a variable resistor isn’t going to be any different?I don't think I've seen anyone use a variable resistor, in order to be able to adjust the value in case of drift over time, would it be a good idea?
I don't know if we'll do the AD202KN solution, which costs a lot, but it's an easy solution.
The AD202KN is no longer manufactured, hence the high price but ‘beggars can’t be choosers’ if you want to fix the issue properly..