Please see the attached doc. 

I think the conclusion is that if the AS1 RoC error is not significantly more than 1%, then with some adjustment of the AS1-AS3 distance (~ 1 cm), we could find a solution that simultaneously makes the AS path mode-matching better than 99% for the t- and s-planes. 

The requirement of the LO path is less strict and the current plan using LO1-LO2 actuation should work.