Doesn't matter where you are (or claim to be, I'm sure that for your own safety you are very far from UAE), these certificates are issued by the FTA itself, and there's online verification for them.
It depends on your home country/current country of tax residence. Some countries will let you off the hook more easily as soon as you stop spending time there and cut your ties with them, others are more strict and will require proof of
tax residency somewhere else.
If you're able to disclose the name of this high-tax EU country, more specific advice can be given.
If that's not possible, as a general rule, I'd advise to become an actual resident somewhere for the first couple of years, and spend 6+ months a year there. So, for example, become a tax resident of a cheap country in SEA (most don't tax foreign income), or a cheap EU country with low taxes (
Romania and Bulgaria come to mind).
That way, you'll leave your current high-tax country without raising major red flags, and if challenged, you'll be able to show that you were a legit resident somewhere else.