I have a bike with a similar setup. I think you have to realise that when you mate an old frame with new parts, or vice versa, there will be some compromise. If it still shifts then probably better to leave it alone.
Other solutions include;
filing the bottom of hanger slot to let the mech sit lower
use a band-on mech clamped just below the hanger
get a mech with a different shape cage. I found a triple front mech that did the job.
I have a bike with a similar setup. I think you have to realise that when you mate an old frame with new parts, or vice versa, there will be some compromise. If it still shifts then probably better to leave it alone.
Other solutions include;