SINCE YOU STILL HAVE A "PERFECT" NOZZLE CHECK, i will propose an experiment.
we have a chinese knockoff of the print head doctor . when people ask me if it works, i say yes, if you use it on a good head.
you might want to call the print head doctor in canada & speak to vlad, the owner/inventor
see if he thinks that overnighting the printhead to him for treatment would be a viable idea
Recovery fluids for Print Head Doctor
digitalsigntech.net
i think vlad would give you an honest opinion, and i know they will do a competent job of cleaning the head. (he has a
"chemist" who fine tunes the recovery fluids for different chemistries and different printhead condition)
NOT SURE if this is a viable idea, but, i would be considering it, if it was my printhead & machine
might be the potential to save quite a bit over the price of purchasing and installing a new printhead.
overnight shipping is not cheap, and i am not sure of the workload you would have to put on hold for a few days,
it's just worth considering. i have thought about suggesting this in similar situations, but, i t seems you MIGHT be the
perfect test case