I picked up a small roll (0.5kg) of a translucent blue TPE flex filament to try out, and started with a dead simple rectangle as the sample print. Probably wise that I started with something small:
Fairly certain that’s not where the filament is supposed to go. Clipping the loose filament, and opening up the pressure latch for the extruder stepper, I was able to pull out the jammed TPE filament.
The filament that remained in the extruder and hot end pushed out cleanly when I setup a spool of ABS and loaded the new filament.