If I recall correctly from our interview with MNEE, they can accept any stable coin, it then settles into MNEE, and the merchant can decide from there what they want to do with it. 1. They can hold it in MNEE, then earn a 2% yield on the balance (I believe monthly)
2. They can cash out into fiat, or
3. They can send it to a custodial wallet via ERC-20, or 1Sat.

Here is the episode if you'd like to watch it:
https://youtu.be/v_wr-jA8hp8

P.S. The video is only 1h45m, Todd just happened to upload it with two copies of the recording back to back.