I find the bomb kit absolutely useless because you have to be within melee range to use it and an engineer in melee range is a dead engineer.
This means you can’t use it in dungeons, PvP, or PvE situations that are against bosses or champions.
My suggestions is to replace the bomb kit with something useful like a rocket launcher, bazooka or sniper rifle we can actually hold and use similar to the flamethrower but more focused on high powered damage on a single target.