Which Infra Red film did you use?
THe more I think of it, the more convinced I am that, using the R25 filter, there does not need to be any "compensation". Considering the cut-off characteristics of the filter, the only light that will get through will be the light that is seen while focusing - directly.
I notice that on the newest Hasselblad lenses, the IR reference mark is missing ... and I think the reason behind that was it was causing focusing errors with films like Konica IR, Ilford SFX (? was that the "extended" color sensitivity film?), MACO 750 and 820 and a #25 filter.
I can see where it might be of use with Kodak HIE, and a filter with a high cutoff point like the #87 or #89 - the use of these precludes direct focusing anyway.