In general, I support free buses (for any number of reasons). However, IIRC the dwell time savings on the 28 during its fare free trial were modest. I don’t remember all the details (and unfortunately don’t have time IRL to go looking), but I do remember thinking that the results of the fare free trial on dwell time was something I mentally filed away as “Hmm that’s interesting and unexpected, I need to look further.”
Maybe the Transit Matters dashboard can help?
Dwell times per passenger went down, but the free fares also stimulated ridership, which made it basically a wash.