Oh, I see.
Basically having current hull-down but cast by the vehicle itself would be a nice usability change, but I think increased range adds to the ability being an issue.
Increased range means you can keep the tank in a safe place. It's easier to support when it's back there. That's why I have reduced sight on mine- it dares you to push the unit up as much as you can. It's not exactly defensive, now that I think of it.
The reduced rotation is important either way, though- it rewards flanking. That's why we have ground-mounted PaK 43s now instead of spinny 88s. With that limitation in place, you can increase the (frontal) effectiveness of the unit by a lot and still make it fair/fun. I'd argue more fun since it gives the player using the ability more to do.
So, finally, my recommendation- implement turret rotation nerf, give back a reload bonus. Non-turreted tanks could get an even bigger reload bonus, as long as they still can't turn.
Relic Entertainment
Grand Master Kimbo 
ImagineThisGameBeingMyLife 
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