So basically, instead of handing custody to ChipMixer for a few weeks, Bob can hold the LN balance (non-custodial) for that time period, then push it back to CM and get & redeem his chip immediately.
Yes. Bob can also open a channel with ChipMixer, if he mixes regularly, to avoid routing failures. The only disadvantage, that way, is that someone who analyzes the chain might realize he's using the channel solely for mixing.
Example #3- Bob opens a channel with ChipMixer, worth of 0.16 BTC.
- Bob sends 0.08 LN-BTC, equilibrating sending & receiving capacity (0.08 BTC sending capacity for both).
- ChipMixer sends him 0.08 BTC on-chain.
- Bob wants to mix 0.01 BTC on-chain, so he sends it to ChipMixer.
- ChipMixer sends him 0.01 LN-BTC.
- Now, Bob's sending capacity is 0.09 BTC and ChipMixer's 0.07 BTC.
- Few days later, Bob wants to mix 0.04 BTC on-chain, so he sends it to ChipMixer.
- ChipMixer sends him 0.04 LN-BTC.
- Now, Bob's sending capacity is 0.05 BTC and ChipMixer's 0.11 BTC.
- Bob can close the channel and earn 0.05 BTC on-chain. The chain analyzer can't know which outputs belong to Bob; at most, they can know that he mixed 0.11 BTC.
Money can be sent back and forth, with the outsiders being unaware of what's happening between him and ChipMixer.
The only issue I see is that having self-custody is more interesting / important the higher the amounts are. And large amounts aren't always routeable through Lightning.
It might be more reasonable for higher amounts, but it works great with micro-amounts if you mix regularly like I do, too. To avoid routing failures, better open a channel directly with ChipMixer's node.