Theme animation customization #70723

Problems

Now flutter by default animates any theme changes. I would like to disable them, because this causes huge frame drops. Moreover I can't change it to some custom one that I would like to. For example, my intention was to use custom theme animation through the package animated_theme_switcher, but it will end up in even more huge performance issues, as I can't disable the default one.
Theme is so integrated into the framework and its animation doesn't have any customization options, that's so much frustrating.

upd i addressed framedrops by removing Theme.of(context) calls in my code and replacing them with static theme variable. the feature request is still valid though

Proposal

Flutter should allow to disable the default theme animation and also to change its parameters.