Android studio - switch active build variant for multi module project

Question

My project have more than 20 modules. Whenever I'm switching active build variant, it does change build variant just for part of existing modules, I have to change some modules active build variant manually. It's frustrating and time wasting issue. I'm asking for help, because I think this problem should has already been resolved somehow - if app has 100 modules, that would cost developer 2 hours to switch active build variant module by module, I believe there has to be some workaround, but I struggled to find one. Thanks for any advices!