That if the input directory had been the derivatives fmriprep directory instead of the raw BIDS directory (and therefore the line --derivatives fmriprep=/data/derivatives/fmriprep \ would no longer be necessary either), then the pipeline would fail to gather the derivatives necessary for ICA-AROMA and fail very early on.
I see that I’m not the first to encounter this: Fmripost-aroma error: 'res' or 'desc' is not a recognized entity - #7 by LawsOfForm (“solution 2 worked but not solution 1”)
I can open an issue on GitHub and share a pre-processed single-subject dataset if that helps with both of these issues.