It's only tax residence for 'remittance bases' if 'not savings'.
We've been grandfathered in.
If you are spending money you are earning, i'd be more worried about getting into issues over not having a local work permit.
Owning/Managing a company FYI is 'ok-grey' but the Thai's don't want to enforce against that (either domestic or international) as they'd loose a lot of VAT revenues off the bat.
And for remittance based, there's NUMEROUS ways to get around remittance tax (if income).
The easiest being 'gifting' from overseas to wife account on-shore (tax exempt) up to 20mTHB.
Other-ways include paying companies overseas arms (or international companies for a domestic service - insurance for example, my kids was 100,000 THB per year︀ on-shore now going through the overseas arm of the insurance company - price comes down,︁ kids insurance covered, no remittance. (white)
Then there's other ways 'pre-purchase vouchers, etc overseas' for︂ expenditure in Thailand. (grey)