does sweet scenting advance the frame by one for non c-gear seeds?
It advances your PID frame yes. For pretty much everything. I am not 100% sure of the interval though. When I looked at PID advancement earlier, I found that SSing on a bike, SSing while standing both advanced your PID frame the same. I also found that taking 1 step on foot in a wild patch, taking 1 step on a bike in a wild patch, turning in place in a wild patch all advanced your PID frame the same. Kaphotics figured out that Saving your game advances your PID frame by 1. However, when I looked at them all, SSing, stepping/turning, and Saving seemed to advance your PID frame by different amounts (compared to each other).
So yes, SSing does advance your PID by some amount. Saving your game advances it by 1, but I'm not sure what the amount is for SSing, although I doubt it's 1.