Depends what you mean by "took out Turkish residency". Obtaining a resident visa in Turkey is no longer as easy as it once was and, as far as I know, you need to be able to show ownership/part ownership of a property. Even then if you get a residents visa and you spend more than 6 months out of the country (except for reasons such as medical or full time education) your visa would be revoked. Furthermore, in my experience in Greece, customs officials do not automatically accept a Turkish residence visa as proof you are resident outside the EU and will look for additional proof you are mainly resident (present) in Turkey.
Unless a deal is done, UK citizens with VAT unpaid boats will have the same status in the EU as Turks so what's the point? Unless I'm missing something, you may as well keep the boat in Turkey as many do now. The boat can visit EU for 18 months at a stretch and you can visit for 90 days at a time.
When answering his post I took it he was talking about interim arrangements until the end of the transition period which could well be years away.
I think you'd face all sorts of problems everywhere you went. You might be able to demonstrate that your Turkish residency proved that you were not an EU resident, and thus entitled to use a non-VAT paid boat, but you'll likely be spending half a day everywhere you go arguing your case with different officials....
In my experience [Greece only] any such questions are asked by the customs official when you apply for your Transit Log at your first port of entry and thereafter you just show your TL when you visit the Port Police. The TL clearly demonstrates you satisfy the relevant criteria.
The problem is IF some sort of deal is done or IF they extend the transition period, I would basically be stuck in Turkey, (or nearby non EU waters), whilst that is not that bad a thing, we do want to sail Europe as well, which I couldn't do at all as an EU resident (current status)