To get a money transmitter license, you must follow those pesky regulations - KYC, AML, etc.

But maybe I didn't understand your original question.

What would be the benefit of having this setup? You can connect BTCPayServer directly to a third-party wallet (and use Breez for LN liquidity).

Strike provides FIAT settlements, so merchants are hedged against BTC price volatility and can easily withdraw money to their bank accounts.