Hi all,
We worked on some schemes to help improve the “nonce” approach:
It involved two protocols:
Multi Nonce = It required two nonces and created a mapping index → nonce. It allows you to define a set of queues and enforce sequential ordering for each queue. It is handy if you want to maintain some ordering, but still support concurrent transactions.
Bitflip = It required a two nonces. Again it is an index → nonce approach, but the goal is to “flip the bits” in the nonce. So you can send X concurrent transactions per queue and require minimal storage updates.
I’d recommend, if possible, to abstract away the nonce concept to allow people to experiment with different approaches. You could implement a basic “sequential nonce” that is plug and playable, but allow others to implement different schemes (like the above) to really benefit from it.