Sipeed is a pretty big designer, but with the West/China issues over chips, I wouldn't take a wager on getting your boards without issue.
You should also expect mid-level documentation if you do get them, it'll be Chinese-only support. This is why I stopped buying cheap Chinese electronics. It's great that you can get them for less, but then you spend 5x the time getting it to work properly.
You should also expect mid-level documentation if you do get them, it'll be Chinese-only support. This is why I stopped buying cheap Chinese electronics. It's great that you can get them for less, but then you spend 5x the time getting it to work properly.