Eric, do you know of any cars where cruise control functions normally? I think it has something to do with the tune and what parameters have been updated. The hardware should all be identical between the cars so the only variable is the tune.
Reverse lockout is the only electrical difference between the transmission so once the pig tail is swapped over for the reverse lights, it's all the same(save for the speedo) so I don't think it's a hardware thing.
I changed the individual gear ratios in my tune to reflect the T56 and updated the rear end gear as well. Aside from that, I don't know of anything else that would need to be updated.
we change all the same things
its very random
i dont know of a car that it works in every gear