The "Calculate Transit Service Frequency (Public Transit)" tool does not allow for any filtering of route types or ids like you would find in the PT/GTFS network dataset. A simple drop down menu or just a text field to input exclusions is needed.
Use case example:
My large metropolitan GTFS feed includes school bus routes (route type 712). Including school routes in frequency analysis is not relevant to the vast majority of the population as they can't use those services. The ability to filter out this mode would make the outputs of this tool reflective of reality for the general public.
Thanks!