GET arguments are not redirected to the spam site because when the url redirection site has received the GET argument, the GET argument would generally be discarded/disregarded before redirecting the user to the spam site.
I haven't tested that but I think it's possible to modify the fragment with Javascript: https://stackoverflow.com/a/4282075
So my idea would be getting looo.ong to create a special client-side redirection webpage that would remove the fragment part using Javascript before performing the redirection with Javascript. And no. Using HTTP redirection response on server side won't work.
EDIT: I've actually seen URL redirection websites that removes the fragment part so it should be doable. Perhaps the purpose of that is to avoid spam abuse.
Yes, this is how single-page apps allowed linking to subpages before history.pushState existed.