Is it possible to have “release” performance of compose in a custom buildType. If so, what is proper configuration for it? Right now I have a custom buildType for a manual testing purposes where:

isDebuggable=true
isMinifyEnabled=true

The buildType itself is not the problem but if you want it debuggable then no, you won't get "release" performance

Do you know what exactly defines what kind of performance I would get? Only

isDebuggable

or some combination of buildType params?

I think it's the combination of debuggable + running r8 (not sure if resource shrinking plays a big part) https://developer.android.com/build/shrink-code

Even if you have minification enabled, debuggable builds still include a lot of — wait for it — debug code, which skews your performance metrics. It will never match release performance, which is usually minified AND non-debuggable.