I run Tidal on two apple computers which sit five feet apart. And also on an iPad and an iPhone. Occasionally I’ll have the Tidal app open on both apple computers at the same time - though rarely playing music mostly just searching since the results are clearer (to me) than Roon’s. However, Roon was playing a Tidal stream at that time.
I’ve done this for almost two years. During that time I have had only one instance where Tidal informed me it couldn’t play my request because it was playing on another device.
Tidal’s customer service has improved greatly. You got a response wishing you a good weekend? Dang. That’s progress.
Use the wife’s. Enjoy.