Proof of residency with a .EU domain?

So I've had a .EU domain for about 5 years, I'm happy with it in every way: I use it for my personal email, DNS, etc.

The only drama is the fact that I live in the United Kingdom, and well, Brexit. Ideally, I want to maintain this domain, so I'm trying to cover all the bases here, since I do not like to change my email or anything that uses my domain name.

To register an .EU domain, one of the following requirements must be met:

  1. Companies that have their registered office, central administration or main activity center within the European community;
  2. Organizations established within the European Community without prejudice to the application of national legislation;
  3. Individuals resident in the European Community.

Assuming my country make leaving the EU and not meet any of the above conditions, I need a solution.

In my opinion, the element of "residence" is the most interesting, and therefore my question is: how will the residence be determined?

I have seen e-Residence through Estonia, which looks very promising.

Or can I simply change my address on the website I use to register my domain? (including primary contact, etc.)? I have a good friend in the Netherlands and I have talked to him about this idea: he has no drama in using his address, but what would be the implications of this?

One option would be to transfer my domain name completely, which I would then do legally, so to speak when the time comes, which makes me ask the question: how do they get a "proof" of residency?