Not to be that guy but apparently Estonian e-residency doesn't hold water in court.
If you're looking for tax advantages you can either a) give up your American citizenship, b) make less than $100k after deductions and claim the overseas income tax credit, or c) move to Belarus where crypto and crypto related startups won't be taxed for the next 5 years.
I'm thinking along the lines of business support services, and being able to get experienced employees with the high tech fields. Taxes should be low for a support office only.