[Freesurfer] group analysis of functional data in custom volume space

Hi Freesurfer Experts, I would like to do a whole brain group analysis of functional data with mri_glmfit using a custom volume space instead of the MNI space Freesurfer provides. This is for primate data. I was wondering what the best way to do this would be.

I have a T1 template in volume space to which I can align my functional data. I was thinking in getting registration files for the EPI to T1 alignment first, then to run mkanalysis-sess in native space per subject, the selxavg3-sess, then isxconcat-sess providing the registration files with the -reg flag, and then mri_glmfit.

Does that make sense? Thank you very much, Caspar