LN transactions are actually onchain "not-yet-broadcasted" transactions. That means are still under the dust threshold rule. That doesn't mean you can't do it, only that are not "incentivized" to be stolen. It will cost more to stole a dust tx than to close a channel.

That's why I will say it LOUD: custodial accounts under 50-100k, even 1M ARE JUST FINE! And not just that, but will relax a bit all this crazy-mania with self-custody.

Yes, self-custody is a must, but not for meaningless and joke money.