Every couple of days, I have to newly login on some device. Presumably because you limit the number of simultaneous sessions to 2 or something. Which just isn’t a reasonable amount. I use the playground on my desktop machine, my phone and my tablet. And the only reason I don’t use it on even more different devices/browsers is just this limitation. Since you’re billing by tokens anyway and so no risk for abuse, I don’t get why you would do that.
(What makes this even worse for me is that as a somewhat privacy conscious person, I use Cromite and to have to repeatedly pass your puzzles there - which simply don’t work well because the buttons sometimes don’t react to clicks.)