I'm not sure about that. When all the SSPs are run by one entity, how self-custodial is it really? Sure, you can unilaterally exit, but that's only a small benefit. Privacy-wise it's much worse than LN, because it operates with similar properties as the main chain. You're going from trusting one LN custodian to trusting another LN custodian LightSpark) on a much more transparent/trackable chain. I really want to like Spark (and Ark), but it doesn't seem like its glaring and serious issues are addressed yet. Until such time I advise everyone to stay away from it. It rather seems like everyone is pushing Spark because it's easy, and legally qualifies as "self-custodial", so gets around Google's recent KYC requirement.

Spark is just literally as bad for privacy as a custodial lightning service, not better not worse. But add the unilateral exit choice. So how is it not an improvement?

Put one of your txids/adresses into

Sparkscan

Sparkscan

Explore Spark balances, tokens, and transactions.

and then say that again.

You perfectly know that: 1- they could chose to make the explorer private if they wanted to 2 - people don't do tx within the Spark entity and just use it as a LN wallet. I know its still possible to find your spark adress through your LN invoice if you are technical enough. But as soon that they stop reusing address this almost stop being a concern because most of Spark txs are in fact LN swaps. So it breaks all deterministic links for an outsider. But the main flaw come from the fact that they made the explorer public. WoS could have also made their database public before bein on spark. What I mean is that the problem come from a choice from this specific Spark entity not from the protocol itself.

*sparkle sound effect*