"Looper" tokens (opt-in ERC-20 and ERC-721 to prevent spam airdrops) are going to be the baby-steps toward my eventual replacement NFT token standard that I have been noodling around with for the last year.

For a few years I scraped and processed every single NFT ever minted on Ethereum. And it gave me some opinions.

Blockchain developer, scraping and smart contracts.

In particular: using a URI for token metadata is a bad fit if you are trying to assemble on-chain data into a data URI. In my experience the majority of NFTs did it wrong and it took significant custom intervention to process them. and the metadata properties are underspecified.

To be honest though, I saw so many NFTs that were so poorly constructed that no spec would have made the developers do the right thing. If you can't even construct a valid JSON document with matching quotes, no one can help you.