Because the Mechlab is planned, simply removing overpowered variants doesn't help at all; they'll come back to haunt us eventually. This is a Beta, we're supposed to be testing for this kind of thing. If an overpowered loadout is discovered then use it to highlight needed balance adjustments, don't just try to shove it under the rug.
From what I recall in the last thread about the Vult B, there was some disagreement as to whether it really is overpowered. Personally, I think it is at least somewhat - beatable, but still ahead of the curve in too broad of circumstances (such as the entirety of SA).
The issue is the mass chainfired SSRMs, of course, which just happen to be currently confined to this one mech. Very easy to use with hardly any aiming needed, and constant screenshake. The screenshake especially is what causes so much frustration, because many times you just can't return fire unless you get lucky.
A couple of my own thoughts on how to improve this:
1) Reduce screenshake based on tonnage. Since heavier mechs have to rely on tanking hits more than avoiding them, and thus end up most hampered by screenshake, reduce the amount of shake they receive to compensate. This also distinguishes Assault mechs as being the best able to bull through heavy fire while bringing their own guns to bear. And really - wouldn't an Atlas shrug off a few missiles easier than an Uller would?
2) Reduce screenshake when crouching. When crouching you're a much easier target, but you're braced against impact and can keep your aim steadier while taking the hits. Of course, a Vult B could just rush around behind your firing arc... unless you have your back to a wall (or a 360 torso), which brings in tactics and positioning. And this gives another function to crouching, which is currently just for AA and missiles.