I don't think so. As I explained, royalties can easily be calculated. They are quite reasonable, between .02% and 4%. I don't see this as an insurmountable obstacle.
Regarding the obligation that the product not be used for commercial purposes, the 25% threshold is in fact viewed as a disincentive by generic drug manufacturers. They made this clear to us in their submissions following the release of our discussion paper. The risk of litigation discourages them from participating n the regime. At least, that's the position they have taken.