This is just a simple rerun of arbcav from #7995 but with the PR2/3 RoCs set to 600, instead of -600. Overall g-factor = 0.922, and the modes are well separated:
This doesn't take into account the effect of traveling through the substrates (still working on it). It assumes the PR2/3 have been moved such that the cavity fold lengths remain the same.
This is something that we need to keep in mind: we will need to adjust the position of the PR2/3 to keep the fold lengths the same.