Apple’s licensing terms for macOS permit only the licensing of one unit of Apple macOS running on one unit of Apple hardware to one customer for a minimum term of one day. There is no option to purchase a virtual-machine or other shared-instance license when macOS is involved.

(Nitpicky points: I believe the customer can do whatever they want with their licensed cloud Mac hardware, such as dual-boot different releases of macOS or virtualize to their heart’s content, as long as they are the exclusive user of the Apple hardware underlying any instances of macOS. “One customer per Mac per day, no more and no less” is probably a better summary in hindsight.)