With #80246, we added a feature switch for RuntimeFeature.IsDynamicCodeSupported. Previously when you published a trimmed CoreCLR app, RuntimeFeature.IsDynamicCodeSupported was hard-coded to true, so any logic switching on that property was eligible to be trimmed. For example:

When you publish a CoreCLR trimmed app, the ReflectionMemberAccessor class could be trimmed. Now that we have a feature switch, the property is no longer a constant.

We could enable this by setting featuredefault=true in the ILLink.Substitutions.xml file, but that runs into the issue described in #96539.

This issue is to track enabling this for trimmed CoreCLR applications. It is blocked by #96539.