When displaying a list of inhereted classes(much like we do in URP for ScriptableRenderFeatures) if one of those classes fails to compile or goes missing, the other classes in the list become invalid too, making this very volitile.

Repo steps:
1. Open attacthed project
2. Select the 'renderer' scriptable object
3. Notice a list of two 'ScriptableFeatures'
4. Make one of the classes(ScriptableFeatureOne/Two) fail to compile either by changing code or removing from project(with being able to return it)
5. Select the 'renderer' scriptable object
6. Notice that the list is unable to draw correctly as it fails to load one of the classes
7. Return the failing class to it's working condition
8. Notice the list on the 'renderer' is now back to working fine without any loss of data

Expected results: Only the class that was failing to comopile/be found should be erroring out in the list, not all of the classes
Actual results: All classes seem to fail to draw even though they exist and their data is intact

Repoed in: Unity 2020.2.0a18 but this has been the case since when PolymorphicSerialization was introduced