The simple Fed contract

 It boils down to Treasury hiring the Fed to manage the tax dollar exclusively as a Due Process, non profit banking board. Treasury retains a specified double spending contract. Deposit insurance become an optional market priced service. Current reserve banks become founding members, trusted ledge keepers for the Swift hierarchy.   Treasury collects a small, defined  monopoly fee. No more seigniorage  Almost the whole Fed balance sheet goes back to Treasury along with their double spending power.

The markets which now expect 15 years of bank taxes expect 15 years of direct double spending of the same predicted amount. So you can see the revenue sharing is a must.

Another key point in the contract. The double spending is Treasury discretionary, it consults ex post. the spending. It has the most rapid response.

Regulations.  All I can say is that at some point a vendor will offer a complete set of contracts with all regulations and taxes cleared, and some vendors will not.  The Swift bankers can be made to at least resell the former. That is, they make fully regulated baking available, as a service.