The development of all the ethereum-style defi ideas on lightning is very interesting. Looking forward to how this space will develop in the next years.

Isn't synthetic assets only 1 step away from nfts?

The paper:

Synthetic asset smart contract for the Liquid network https://vulpem.com/synthetic-asset-smart-contract.pdf

Github repo for Covenant code: https://github.com/vulpemventures/synthetic-asset-smart-contract