I noticed that when I set my profile to available and didn't get hired for sometime (even 2 weeks), my JSS gets down madly something like from 100% to 83% or someting.
I'm not sure if other factors contributes to that, but I think it has something to do with availability.
I do have my own published and underdevelopment apps and games, but when I get a good offer from a client, I would pause my own stuff and work with a client, then continue on my own stuff afterwards.
If I tried and set my profile to available and didn't get the right invitation, would my JSS get down again?
That would disencourage people from trying to activley search for opportunities on upwork.
However, the secret ingredients to JSS calculation being secret, everyone is allowed to try to guess what they could be.
I hope someday we'll find out - maybe on doomsday.
I routinely turn my availability off and on.
Sometimes my availability setting is set to "off" for months at a time.
I don't think Upwork "punishes" freelancers for either status.
I have never heard of this having an impact on JSS.