> I'm considering setting up as an Estonian e-resident soon though (https://e-estonia.com/solutions/e-identity/e-residency/) to change where I pay my taxes.
Talk to a solicitor before you do this unless you want HMRC to come a knocking. Estonian eResidency is not actual residency, and it won't change the country you're resident in for personal tax purposes. You could set up a company in Estonia, but if you're an independent contractor and all the profits from that company flow directly back to you HMRC may again have questions (and you'll still have to pay taxes on the dividends you receive at the UK rates).