This could be used in conjunction with third party payments, but it wouldn’t enable them, necessarily. The invoice could easily be the destination of a payment from a DEX, and the patterns I’m using would hopefully be useful to someone building a DEX as a reference.
As for queries, we could probably certify queries against the invoices with some extra work. I wouldn’t commit to proper queries anywhere else though, because the priority for this project is to abstract multiple types of ledgers whose interfaces haven’t been fully established yet, such as BTC and ETH.
Will this mean that an inter-canister query implementation gets prioritized in the coming few months
Probably not. Queries within subnets are possible, but there’s no movement right now on cross-subnet queries
I’m leaning toward releasing this as an MVP that people can self-deploy and offer feedback on for a while first, and then we can possibly set it up as a central service with an SNS down the road