I’m 90% sure that i got shit rewards after deserting (obviously), and then nothing at all after rejoining even after finishing top 3 or 4. My recollection is that i had maybe 40 kills, some rally score, assists, point kills, etc, and got literally 0 xp/silver at the end of the match. Maybe I’m misremembering, but I don’t think so.
Like I said, i will still rejoin a game i disconnected from because i think it’s the right thing to do (if you desert because you don’t like the game mode or something, fuck you, all deserters suck, make the game worse overall and then complain the game is worse), but from what I remember, rejoining a game in progress cost me 20 minutes and netted me 0 extra xp/silver/etc. maybe I’m mistaken, but that’s what i remember.