Im trying to use the available data posted here to figure out what is the best offset for a 20 x 10.5 wheel for the rear, using the online Wheel Offset Calculator and the 20" wheels posted here with the min and max offsets,
TSW 20 x 10 +40
KD07 20 x 10 +55
Since the above wheels use the same width but different offsets, this means we have a range of 15mm (0.59in) we can work with without any clearance issues. So effectively a 20 x 10.5 with an offset from +46 to 49 will still be in the range of the TSW/KD07 wheels and should clear the inside since we are not going any further in towards the strut when compared to the KD07 and not extending out anymore when compared TSW wheels.
I feel the rear TSW wheel is a little bit too flush with the body, so a 20 x 10.5 +49 would be perfect, it will retract 3mm compared to the TSW wheel and will not be any closer to the strut when compared to the KD07 wheel, so it shouldn't rub.
Is my above assumption correct, I am just getting to learn how this offset stuff works.
I used the below Offset calculator,
https://www.1010tires.com/Tools/Wheel-Offset-Calculator#