Thank you for your feedback, it seems the community generally wants a larger penalty. I am personally in the boat that a 5% fee is adequate at this stage and is a valid penalty to disincentivize people from using it freely. It is designed to be a slap on the wrist and not something prohibitive so that no one ever uses this feature.
However, if we find people to be using it too often, it is definitely possible to increase the fee with another proposal.
Regarding DEC-B, once lands 1.5 comes out I believe there will be more uses for it.