I was on Thursday in Chaeng Wattana immigration Building B.
The documents they asked for:
TM7
Copy of passport, TM6, latest arrival and SPV page.
Copy of the Quarantine hotel booking, proof of payment and last PCR test they provided.
Health insurance (minimum coverage of 100.000 USD for COVID-19 treatment. Apart of that it must cover the whole lenght of the stay (minumum coverage of 40k tbh for outpatient and no less than 400k for inpatient) Important: it must be a Thai insurance company. I got one for six months through a friend agent for 21k (2k agent fee)
Rental contract and proof of payment.
I hope it could be useful for someone.
Best regards,
Ivanex
@Rdimbus