How do I report fraud or App Store rule violations outside of a refund context?
Fraud should be easy - engage a lawyer and/or your local small claims court. If the fraud is contract based, monetary remedy Is likely from small claims court in your jurisdiction at little expense to you in time or legal fees. 

For wanting to police Apple and/or developers on what you find to be in violation of Apple policies but not actual laws, I stand by my answer to the question you linked. 


Unless you have a developer relation and another developer is infringing on your work, you (the consumer) can only really ask Apple for a refund or just delete the app and send them general feedback when the report site has an explicit 90 time limit documented. 


If you feel you have an exceptionally serious issue, why not engage store support chat to validate how Apple would want to hear about the specifics?


https://support.apple.com/contact