It looks like there are a few different issues reported in this case.

1. A stripping issue that causes the error "InvalidOperationException: A suitable constructor for type 'BananaTree' could not be located. Ensure the type is concrete and services are registered for all parameters of a public constructor.'"

This is the intended behavior of managed stripping when set to Medium or High. Because the provided code relies on reflection to find and create the BananaTree class, and managed code stripping has limited support for finding all usages with reflection, that class's constructor gets stripped.

One solution is the workaround provided in the code, which is to have at least one instance of calling the class's constructor somewhere in the code. Another option is to create a public constructor on the class and mark it with a "Preserve" attribute to ensure it does not get stripped:

[Preserve]
public BananaTree()
{
}
The reason why a "link.xml" did not work is because "link.xml" files never apply to the project's "Assembly-CSharp.dll" assembly, which is where all the user project code is compiled to.

2. When code stripping is set to High, there is an additional error related to stripping a type from the class "Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope". Because this class IS in another assembly, it can be added to the "link.xml" in order to be preserved:

<assembly fullname="Microsoft.Extensions.DependencyInjection">
<type fullname="Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope" preserve="all" />
</assembly>

3. The "NotSupportedException" caused by an unsupported internal call in IL2CPP ("Unsupported internal call for IL2CPP:Assembly::InternalGetAssemblyName").

This happens regardless of stripping level, and is a specific limitation of IL2CPP. We don't plan to support this in IL2CPP, as it would require the player build to carry around extra assembly data that would increase code size too much.