The kit's bomb radius is nearly non-existent. I don't care if Xorgon says it is "x" blocks far, I tested it with Grivnok and the bomb goes off when you are one single block away and if you back up or run past it fast enough, it doesn't even blind you from that range. The kit barely works and even when it does, it is underwhelming. I'll ask you, why don't you ever use agent if it is perfectly fine? I know I don't use it because I know the kit isn't fine it barely works.
I think Magician might be up a tier now with the recent change making it so you can't pig teammates. It allows you to just use it in the middle of a fight now without having to worry about pigging your teammates.