Using a slightly outdated 2.31.2 WIP version (but I didn't find any notes about this getting fixed), if the application registers a funcdef such as by

engine->RegisterFuncdef("void voidFunc()");

the following script reports a compilation error:

shared void call(voidFunc@ f) {
	f();
}

According to the error, "Shared code cannot call non-shared function 'void voidFunc()'". This appears to be unjustified, because funcdefs are supposed to always be shared, all other parts of the application-registered interface are accessible from shared code, and the error only occurs when the function is called, rather than on any other use. The same error doesn't occur if the funcdef is defined within the script.