When you have 1 or more Gemini selected, right clicking on the stealth button turns stealth on/off for ALL Gemini.
And the same for Revenant.
Alternatively you could add buttons to the Cybran T3 air factories to turn on/off stealth for all Gemini and all Revenants. But I think it would be better to modify an existing button that's already on the planes.
I just tested, and RMB is the same as LMB.