Thanks for your replies, guys!
I thought about entering TH on visa exempt to avoid the two trips to Munich for the Non-Immi-O.
But I fear time could run out after 14 days of quarantaine with only one month left for the extension-process. I have to start all over again. To get the one-year bank statement takes 2-3 weeks. If I'd be testet positive during the time in ASQ (got my two shots more than 6 month agoin, many false-positive results with PCR) I would be in trouble.
The health insurance is no problem. It is mandatory as long as I am German resident and it covers each and everything worldwide.
Anyone here who did his ASQ in Amaranth Savarnabhumi Airport Hotel? The reviews are ok and it seems quite bearable to me (balcony, smolers room, 7E-delivery).
Have a nice day!