It's not non-custodial while your sats are in LNMarkets.

Synthetic stablecoins of LNMarkets is also cool idea.

For short term we must think about best ways how to hedge BTC/fiat price volatility for merchant adoption. Hedging that makes sense even if you as a business owner are BTC maximalist and believe in hyperbitcoinization, as your daily expenses are most likely fiat denominated.