bpjackso
I think that the discontinuity in sensitivity will be a problem (with RMs only at the start and end) unless you have very little drift. Are you importing the data as 1 or 2 vits? If it is 2, you might be able to do something by enabling spline "discontinuities". E.g.,
Maybe it would be worth scattering several RM measurements throughout the session? That way if it crashes mid-run, you can still model the drift in both parts.
All the best,