Dunder was made to easily onboard new Blixt users with opening channels from a LN payment. Same as is doing Zeus with embedded node. Only that Dunder is also offering little bit of inbound liquidity up to 400k per channel. This way new users could also being able to receive more after the first deposit.

Imagine you are onboarding a new user that have no coins whatsoever in onchain or LN. You, as his mentor, you pay his first LN invoice to Dunder server and he gets the sats straight into his new Blixt wallet.

This limit of max chan is set by each Dunder LSP operator..

Now, to answer your question. Any other mobile node could open a regular channel with Blixt node but not yet supported with 0-conf wrapped invoices. This will be fixed in the future by making a LSP standard code for all types of LSP.