Has anyone tried MS-ing with this product? (https://www.upsideaccount.com) I'm guessing shutdowns would be a concern but, if not, it actually looks to have potential.

Loading:

Max load of $500 per 24 hours and $3000 per 30 days @ $2.50 per load from CC plus 1% cashback on funds loaded (only with the Edge plan @ $29.95 annually, and no cashback on GD loads).

Assuming you can really max out without being shut down, that's six $500 loads @ $2.50 (i.e., $15) + $2.50 (annual fee $29.95/12) - $30 cashback = a net gain of $12.50 per month.

Liquidating:

Other than presumably MOs, it claims to have an online check writing service @ $1 per check issued.