Is the alpha stable? can i opted in and out easily like the reddit beta?

tildes.net and some firefox extention (for reddit) implements it this way.

It can still be problematic, if i go to a thread with 100 comments and read it, come back and there are another 100 comments i might not want to read them all in one sit (e.g. because it is late at night).

It's interesting that all these "modern" platforms still don't have some of the usability benefits of email (while having their own benefits ofcourse) , I also wonder if this is part of the reason the linux kernal still uses email for communication.