I like this a lot better with JTs than JTo, but honestly I just don't know how much value there is in 4b light in a $8fo this early. If we were deeper and ITM etc then I think there is certainly some value and maybe there is from this villain as well but just my general philosophy
Stack sizes behind and it being your first pfr would make me think he isn't that light.
When we 4b light, ideally we want cards that block a nutted 5b shoving range. KQo makes a very good hand to do it with because we reduce the 6 combinations of KK and QQ to 3 each.
If I was confident that he was 3balling light with that sizing I would 4b bigger because we're out of position and all that stuff. (I don't think his 3b size is great fwiw)