XF 1.2 Making theme override optional

[Warchamp7]

I have a forum where I am overriding the users chosen style with a tailored one, I'm okay with this being default, but I'd also like to give users of certain usergroups the ability to disable the override, and use their chosen theme.

What's the best way to go about this?

 

[Jeremy]

Please do not cross post questions.