Format cell as a radio button (in addition to format cell as a check box)
Create the possibility to make regular cells look and behave like a radio button (that auto-detect adjacent radio buttons). This prevents having to add separate controls in a worksheet and keeps it fully integrated. See file for a working demo.
Peter Susi commented
Agree - the separate "Form controls" are overly cumbersome, and don't work in excel online. Let users click on a cell to set it true/false