find_package_handle_standard_args: X_FIND_REQUIRED is case sensitive
I've just noticed that with find_package(Foo, …) find_package_handle_standard_args then checks Foo_FIND_REQUIRED, which was confusing, since otherwise packages appear to be handle case insensitive.
I think it might be good to check this case insensitively - after all it will also use uppercase with FOO_FOUND.
See _FPHSA_FAILURE_MESSAGE in Modules/FindPackageHandleStandardArgs.cmake.
Also applies to _FIND_QUIETLY then probably.