>>2937829
>and you’ll have a PEEK machine, no?
Not quite. The hotend/thermistor/heater need to be built to handle the ~500C needed, and most are not. Same with the bed/magnets/build surface. It needs active chamber heat and a good printing drybox.

>>2937835
>How would the softening of filament in the hotend make it harder for pressure coming from all the way back at the extruder to force it out?
Normally, the filament is a little narrower than the tube it moves through, which lets it feed easily. When a filament softens from heat creep, the feed pressure causes it to squish and widen to fit tightly in the tube, greatly increasing the force required to push it through. If you have a stiff filament and good extruder, this can carry on for a bit, but it can get to the point where the extruder skips or the filament buckles (more common with flexible filaments).

>Is it possible that my heatsink is not heatsinking well enough because it's become filled with dust/gunk?
Yes. Higher ambient temperatures also contribute to heat creep