That's up to your airline . I've never been questioned coming for 60 days but arriving on visa exemption 30 days ( Aust. Passport) . I've never had my partner write anything . They did call her once ( during the pandemic as I put down my Quarantine hotel details on my TM6 card when they had them )
Ouch. His travel insurance for medical would be expensive .. ?
I remember my mums was 2500 Aud ( and this was only company that would insure her due to pre-existing conditions ) just to travel to Spain from Australia. My son and I together was 90 dollars for the 3 week duration ..
But if you do overstay . Just don't get caught by police because your consequences would be a fine and a ban of up to 5 yrs . So I think a 1900baht extension pays off