You should be able to do this by enabling Allow users to upload regular files in the ACP, and leaving the allowed extension list empty, or just putting in the extensions you want to allow.
I hope that you do realise that allowing all file extensions is rather dangerous without extra precautions.
Leaving the allowed extensions list empty is something I would strongly advise against.
The npm team tries quite hard to come up with a system to deliver packages efficiently and reliably, so while I have my grievances, I can't deny we'd be lost without them!
My hope is the client code continues to improve as well 😄
