I could write down a seed phrase on a piece of paper and hand it to you, and that's a completely offline transaction.
It prevents the parties of a transaction from double-spending balances behind each other's backs.
It also doesn't require trusting the other party once a transaction has (almost instantaneously) completed.
The fact that I even have to ask you already demonstrates how shitty your third layer is compared to Lightning, not to mention all the other obvious ways in which it's infinitely worse.
In any case, seeing that I don't have a valid signed BTC transaction from you (because your 3rd layer suuucks), you don't want to allow free exchange between your layer and the upper layers, and I wouldn't want to bother with court litigation even if you were serious, well, have a nice day and good luck with your third layer lol