After the bombardment by Israel last year Russia sent a ton of Manpads, so they are certainly available. We've seen a very close call by an fa18 from a manpads. It's likely that Iran has passive sensor networks that they can use to spot patterns and provide forewarning to manpads teams.

I think you're right about stealth not being quite the game changer that it was. The Houthis were able to give f35s some close calls over Yemen last year. They're of course armed and trained by Iran, so we would expect to see some hits.