crefl | runtime library and compiler plug | Reflection library

You don't need reflection. One way is to use an interface:

You are creating a new module layer containing two modules and establishing access of one of these modules to the other. However, you actually want to establishing access for the currently running main method to one the these modules.

The currently running main method can’t be part of the new module layer it just creates. Assuming standard launcher setup, it belongs to a Controller module loaded by the system class loader as part of the boot-layer.

So, instead of granting access to a new module of the same name in the new layer, you have to change the code to grant access to the already loaded Controller module. Since the new Controller module of the new module layer serves no purpose then, you can remove it from the layer configuration.

The premise of the question is incorrect; PropertyInfo.GetValue works just fine - here used with your method with zero changes:

I can't think of a solution that's significantly different to yours, fundamentally it feels like it's a custom logic to determine whether a property value is "empty" or not.

Perhaps a pattern matched switch expression might make the code a little cleaner, however, for example:

You are right, this is not an easy problem because of erasure. However, I think it is not unsolvable.

The fundamental principle should be to follow and replace the type variables with actual parameter types all the way to List.

Consider these two classes:

Use the -as type conversion operator:

Your class and record aren't equivalent: records have private fields.

Class#getFields() returns public fields only.

You could use Class#getDeclaredFields() instead.

You need to specify the BindingFlags to be NonPublic in order to find the private method.

I am not sure what is the PrivateObject but this should work (you may change it a little bit to make it suitable for your needs):

In CRTP, T is incomplete in class MyClass : Self {};.

You can add an extra check in a method which should be called/instantiated (such as constructor/destructor):