"- bids from the holder include a phantom x% (bid is worth more than what would actually be applied to the cap)"
This was my suggestion and I don't want to be overly argumentative here.
The feedback so far is that it is too powerful.
I'm not sure how this can be too powerful regardless of what x% is. I think, logically, for very low values of x, it should be useless/not worth the complication and for very high values of x too powerful, with some midde ground in between. Now, I'm not saying I know exactly what very low / very high / middle ground are, but I do think all three must exist.
But if somebody can explain to me why (extreme example to prove my point) a 0.01% "phantom increase" would be too powerful, I'd love to hear it!
(assuming of course we move to a very high max or no max)
I second scully's opinion that if Bird rights only allow for 15% max increase instead of 10% just isn't worth the extra effort and complication of having them at all.