They can also use cash flow from the software business towards dividend payments. STRD is non-cumulative perpetual, so they can just stop paying that if needed, and STRK can be paid with MSTR stock. That leaves STRF and STRC. STRF has a pretty small debt obligation, and STRC does not have a fixed interest rate, so they can lower the yield as needed.

Something really catastrophic would have to happen for them to sell bitcoin.