On older bikes it had the effect of flattening the seating area and prevented sliding forward. The rider's weight really isn't borne by the plastic tab of the seat.I looked at doing this today. I just happen to have some of the chair leg feet in my junk box. It seems like it might make a slight improvement but I am concerned about the front attachment because it is made of plastic on the 2021. I am not sure I want to drill, etc into the plastic support.
My gut feel is the root of the problem is seat foam being too soft.
The rubber pads pass the weight of the rider thru the seat to the frame. Do the rubber pads on the 2021 bear on a plastic support or metal?