If you are a UK resident and have offshore companies to evade UK tax, that is a completely different thing. But if︀ you leave the UK and stop being a resident there, then the HMRC cannot claim︁ anything.
You do have to keep in mind the days you spend in the UK︂ though, and you probably can't stop being a resident until 2024 (you've been too much︃ in the UK already this year).
But I agree, you should get a second opinion,︄ preferably of someone with international tax experience.