Hello from Russia.
I'm playing SM since 2002, and there is my opinion about VBB.
I think that 100% pts penalty ( or bonus for adversary ) is ruined whole idea. That simply means that my opponent that made HALF of normal job will take FOUR TIME bonus.
Will you take any cruiser with compulsory fleetcomm, that needs only four pts of hull damage to bring you to defeat? I will not. Can you name any ship that brings over 200 pts to you enemy for only 4 damage? I cant.
Maybe I should take battleship? No! the reason is same. For only 2 additional hull damage I'll loose another ~200 pts. I cant recall any ship that grants my opponent near 400 for 6 hull damage.
I think that there is no need in introducing any penalties for having VBB via shifting bonus for crippling or destroying VBB.
Instead you may just adjust point costs.
Any SM fleet, even consisting Imperial\Chaos ship as VBB, will newer match for hardcore chaos, or any raider type fleet (except Orks ). So you there is no need to penalize them for "doctrine deviations"