I sat with a local banker here in Georgia and hand wrote a declaration that my citizenship
country has a statutory residence test and that due to not being there for the required time I cannot be tax resident there. She took it to the bank's compliance office and had my actual and legal addresses in their system changed to my local address here, where I had the same status as any tourist. I was not tax resident in Georgia at that time. I was tax resident in Thailand
at the time, but as a non-Thai citizen this probably wasn't obvious or relevant. The big advantage for me was to have bank statements (with address and transactions) and bank reference letter
for KYC purposes (I no longer had a Thai B visa and left as a tourist).
Someone else I know attempted the same and was refused; they said he would need a residence permit to change the legal address. This would be similar to Dubai, where legal residence is more likely to be checked by a bank than tax residence.
I think it helps to have chatted to the bankers in the past, make sure they understand your circumstances, what you do, etc. They can see that your bank activity with them makes sense. From my previous experience of UK banking (including so called "private" banking with a large high street bank), you don't get to encounter a genuine banker in person, so it would be harder to maintain a relationship if you live on a yacht somewhere in the ocean. If you say you live in Thailand a UK bank will almost certainly close your account.
I expect the Channel Islands banks are more approachable, but you need quite a large deposit to open with them.