What even is the restriction on returning JSON? One of the examples is explicitly how to return JSON https://developers.cloudflare.com/workers/examples/return-js... From the terms > 2.8 Limitation on Serving Non-HTML Content > The Services are offered primarily as a platform to cache and serve web pages and websites. Unless explicitly included as part of a Paid Service purchased by you, you agree to use the Services…
2.Cloudflare may, with or without notice to you and without liability of any kind, temporarily limit your storage and/or the number of requests you can make or receive using the Developer Platform for any reason (in its sole reasonable discretion), including without limitation, if processing such requests would put an undue burden on the Cloudflare network, adversely impact the Service, or otherwise threaten the integrity of Cloudflare’s networks.
To be fair I'm using lots of requests and bandwidth so could be reason, just if only I got an email about that before shutting everything down.