For a normal E30 (non-M3 )or E30 M3 using a normal E30 rhd PAS (4.1 turns lock to lock )rack I'd say it would be worthwhile.
However, bear in mind the std lhd E30 M3 rack is 3.6 turns lock to lock and an E36 one is 3.4 turns so is not much quicker.

I'd offer up a lhd Z3 4-cyl or 6-cyl non-M rack first before buying to see what work is involved. It has been done on a rhd converted E30 M3 but that also involves a reworked manifold in the first place to fit a rhd E30 non-M PAS rack . Birds converted a number of lhd E30s back in the 80s


What do/did the rally cars use? A stock rack? They used the E30M3 on the Tour de Corse - I'd be surprised if the drivers could put up with a 3.6 turn rack