Can somebody with actual experience please give an overview of the proper products and steps to correctly strip, surface prep, and paint an elastomeric bumper?

I'm a backyard hack and I could figure it out, BUT this is not an $800 dollar used car.

Like is filler primer good to use on a flexible bumper? Or do we use the bumper repair products sold at paint stores fo late model vehicles? Thanks

I would use 80 on a Palm sander if there are many layers of paint. After which when sanding down to the remaining layer I would switch to 120 grit. 180 for the entire bumper then move to a 220 until very smooth, then block hand sand with 320. you need to ensure that "flex agent" is added to the primer and body color paint. Basic body work after this, several coats of primer sand until you have removed all the nicks. sand primer starting at 180, 220 320 to finish. Be careful not to load up on the primer it may crack if its to heavy. Hope this helps