Add a json validator, JSON formatting, summarize JSON.
I use n8n daily and I always come across situations where the json is not in the valid structure, missing a comma, a quote or even a colon. In addition, you need to structure the json to make it more readable. I use external tools but it would be of great help if n8n implemented this feature to optimize flow construction.
I use this site which has helped me a lot when building a flow (https://jsonformatter.curiousconcept.com/?process=true#)