PolymorphicVirtualCaster StaticObject instantiation takes a very long time at app startup #354

I recently updated to a newer version of cereal and it seems like some things have changed.

On startup Cereal creates these "StaticObject" instances now for every polymorphic registration.
My app now takes around 60 seconds to startup, compared to 1 second previously. I'm on iOS with an iPad Pro.

Why does this happen now?
What's the benefit of these StaticObjects?
Can I turn this off somehow?