At the time I went to Cambodia, you could not choose your quarantine hotel (which is an advantage for me, one less thing to bother with). Now or soon they allow.
2000 USD deposit is great for US-Americans or others who have access to USD, but I had to exchange EUR to USD in Berlin at a loss of 5% against XE. It is said Cambodian immigration accepts other currencies and credit cards as well, but there is a danger of being refused by airline, and there are reports of people getting sent back because their credit card did not work.
I got a delayed, but positive reply from Cambodian embassy in Berlin. Processings there in person were much more pleasant than all Thai embassies I have been to (Berlin, Vientiane, Saigon).
I wonder if those visa extensions for those "unable to return home" work when you went from your home country to Thailand for a holiday and want to extend it. Last year, extension of extension (???) was only announced a few days before the current extension expired. I would not want to be in the country and counting days until my permission to stay expires, waiting for an announcement of a new extension and having to leave in a hurry or overstay if there is no new extension. And I wouldn't like going to immigration every time.
I tested positive last year without symptoms. As I see it, Covid is a hyped annual flue. No danger for the majority of the population, only for some at-risk groups.