If you want to avoid taking the head apart, you could take the bowden tube out (at the head) and slide filament by hand (while the nozzle is hot). You don't need to go all the way in, just test the passage in the teflon coupler. If it slides without resistance, then you are fine.
Regarding the spool holder. I mean now, with the new one - did you print illuminarti's test objects?