Dad had leg/foot ulcers that would not heal. Some patients develop this after years on HU. Going off HU seems to be the right move if that's the culprit, but ulcers still may take awhile to heal.

I am 6 years in on HU, but so far ok. I am 70 yo F with ET-CALR.

I think you're right to pursue specialist treatment.

I have never heard of "pure" ET. It sounds like the current doc has something specific in mind with that term. You might want to ask what he means?

I wouldn't have any problem asking my current hematologist if she could send me to to university hospital research specialists if we ran into problems she couldn't handle. Most docs now are relieved when you ask for a referral for something puzzling or suggest it themselves. The referral places like to know your original doc is involved because they get all the pertinent history, and once they figure out the best treatment, they can turn you back over to the original doc.