If you are still running the mismatched shifter/derailler combo, set your cable tension in the middle cog of the cassette. That way when you are shifting in either direction, it's only half as bad. Also, play around with clamping the cable at the opposite side of the intended clamping point. It might change the leverage ever so slightly in favour or out of favour. It's worth a try.
July 2, 2021, 8:09 p.m. - Konrad
If you are still running the mismatched shifter/derailler combo, set your cable tension in the middle cog of the cassette. That way when you are shifting in either direction, it's only half as bad. Also, play around with clamping the cable at the opposite side of the intended clamping point. It might change the leverage ever so slightly in favour or out of favour. It's worth a try.