I have encountered this too. I don't force people to use Signal, but I also don't use any other messenger, so if they want to contact me they will just have the use it and else the content is probably just not that important.

I don't think so. Switching to the new user names is taking them ages.

Seems probable. The first time I tried, I failed the CAPTCHA twice.

I had left time between the following signup attempts after they failed, so I'm not entirely sure whether it was due to this kind of rate limiting.

But no matter what the exact reason was, it worked now.

I'm constantly getting "EOF while parsing a value at line 1 column 0" when trying to register.

Congratulations.

Also available in higher quality in the Internet Archive: https://archive.org/details/tpb-afk