Most of those places you mention are relatively hostile to (foreign) startups, Estonia in comparison tries to encourage foreigners to open companies there.
How open is it to foreign workers on, say, 12-month contracts? Not that it's something I'm looking for right now but knowing it might be a possibility in a few year's time would be encouraging.
They have a specific digital nomad visa in addition to other visa types. I came on an ordinary visa some years ago (American citizen working in tech) and found it quite easy to get visa and bank stuff sorted, that said I was employed by their government.
Very easy to get a short term employment residency for 12 months. You can always convert to the more traditional D Visa if you decide you’d like to stay.