edit: looking at the paper is this not just the lightning network?
At a glance, it's similar with LN. But OP already mention these which makes it different from LN
Users do not need to open/close channel or pay Bitcoin transaction fee neither routing fee at all.
Although there are few thing which similar with LN (and other payment channel protocol) such as
If the issuer broadcast a cheating transaction to Bitcoin network, the creditors will be aware of this in few seconds and they broadcast this guarantee transaction to Bitcoin network as well. Because of high Bitcoin transaction fee, this guarantee transaction will take place in next block, even if other transaction which are using the same UTXO as input existed in mempool.
But this protocol isn't something one could understand by spending 10 minutes to read and understand it, so i might be wrong.