I believe a better solution for the parking lights would be the inline zener diode setup that vendors like Watson’s Streetwork and others sell. They turn the amber lights into both parking lights and turn signals. One is required per side.
As for running a LED flasher can with resistive tail light. I am not sure that would work as too much current could be passed through the can and either burn up the can or the lights would blink two fast. Others might have a better feel for this issue than I.
