In the Options section of the Google Sheets product, there is an open text field for Advanced Settings. The tool tip (see screenshot) has a few examples, but I don't know if this is comprehensive.
Where can I find a complete list of the advanced settings for Supermetrics for Google Sheets?
Sadly, we don't yet have a comprehensive reference for these (it's on the to-do list). Some of them have been turned into the other options you see in that section, some only apply to certain data sources so only appear in their hover-over box.
Many are listed here in the functions reference list under "Settings" (its all the same API backend so even though this is technically a different tool, these still work in Sheets):
One of the ones not mentioned in either that is pretty useful is TIME_DIMENSION_FORMAT_xxxx. That one has it's own guide here:
Sorry we don't have a better list for this. Please let me know if there is something specific you are looking for.