[Denoising] How can conn account for runs/sessions with different regressors/amounts of regressors within one subject?

Summary of what happened:

We have a single-subject design where different sessions use different regressors which we would like to analyze. However, I am not sure how to go about setting up denoising, as it seems the code only ever looks at session 1 for what covariate names are possible (see screenshot of line in question from conn_process). Has anyone worked around this / have any suggestions for best denoising practices? Thank you in advance!

Screenshots / relevant information: