Hmm, now I have a question. If all transactions eventually need to be settled on the blockchain anyway, how does it affect the fees and the scalability? Usually, LN is positioned as a way to send a lot more transactions than the current blockchain capacity, and send them cheaper. And I kinda understood why, but now with the introduction of HTLCs I'm not that certain anymore:

1. Fees: I thought that one can save on fees by sending several payments to the same hub that will distribute the payments further. Since it's all happening inside the channel, it will be registered as one big transaction to this hub rather than several. But my understanding is that HTLC requires a separate transaction output, does it not? The end result would be a transaction with one input and a lot of outputs with hash locks. And since it's different hash/preimage for each LN payment, it would require a separate spending transaction per each payment, right? Then the fees must add to the same amount anyway?

2. Scalability: I thought more scalability can be achieved by transacting off-chain, but if, when closing the channels, we must broadcast the same amount of on-chain transactions to spending funds from off-chain hash-locked outputs, won't it choke the blockchain all the same when we attempt to close the channels this way?

Sorry if the questions are invalid, I've learned about the use of HTLCs in LN just now, so I'm pretty much saying things off the top of my head at this point. But maybe someone already knows the answer.

Upd: actually, having thought about it, something like this would be neat: if someone sends me the correct preimage, I'll just replace my puzzle output of this amount with a simple output giving him the funds, since I know he can take them anyway, since he knows the preimage. But this would clean up the outputs and consolidate them, so that when the channel closes, it's just one clean transaction signed by me and him without any hash puzzles.