Best feature of this app I feel is live sharing

like: http://jspaint.ml/#session:abc sessions are shared in real time

Careful: http://jspaint.ml/#session:abc not really work safe when I clicked on it

Spiritual successor to /r/place?

Interestingly, it seems to lose 1/3 of the inputs I'm trying to send...

Yeah, it's super half baked. I can tell you that as the developer. I plan to focus on collaboration in the successor to this project, Mopaint: https://github.com/1j01/mopaint

(Rather than adding it after the fact.)

How do you do it?