Everyone knows the glorious 2 vortex bombs Electron Vortex and Obsidian Crusher, the only support bombs on par with shiv in their value. Unfortunately, one is locked behind a massive PvP wall that you might not (or flat-out won't, in case you're not US) enjoy going through, while another is event-exclusive. The standard Graviton line, despite all of that, is still just sorta left collecting dust, since it's generally better to wait for the event then to make the normal one.

Like I sorta said, vortexes are a lot like hazes, except there's also knockback support thrown into the mix, so damage is irrelevant while statuses are quite important: Electron's shock can get the mooks stuck after bunching them up, giving you more time to pelt them with brandishes on top of other more general benefits from shock, while Obsidian sill knocks them around after bunching up, but it leaves them with a massive debuff that can break an arena in half when there are menders involved. Graviton, however, just sorta randomly knocks mooks round the arena, hurts a bit, and that's it. Stun would make it valuable on par with the main 2 and give people a decent alternative who don't really want to go through the bullpoop of getting the other ones. Plus it just makes sence, you're getting sucked into a whirlpool and then lanched away with several G forces, that just has to give you a concussion. And I doubt simply chopping some damage off and giving it stun properties would be too difficult on the technical aspect. And if you think stun is a little too generic and all-around usefull for something you can get so easily, you can juts slightly lower the infliction rate.

P.S. Also, the Celestial Vortex. Supposed to be an end-all-be-all Pay2Win weapon on par with the mixers, completely outclassed by the PvP reward that's been there for years. OK?