Just to keep in mind: for compliance circuits, balance check is the only place where we deal with elliptic curves. In resource logics, though, it is one of the most common authorisation mechanisms. For example, in the kudos transfer with the example denomination and receive logic, each denomination function (issue, burn, transfer) is authorised with a signature. In addition, the kudos main logic also requires a signature check. So if we want to try to optimise elliptic curve situation by getting rid of the EC checks, we would have to come up with a new go-to mechanism for such things. One option would be to explore the PRF approach further.
If we succeed to come up with the mechanism to replace signatures, we still would have to deal with signatures the moment we leave our application land. For example, if the action is authorised by some external mechanism, say, Metamask, it would be signed by its key – there are no other mechanisms available, and the resource logic would have to check whatever is authorised.