Ugh.. My comment was meant in the Relay thread, but anyway, it sounds like Relay/GraphQL is designed to not fetch anything that isn't actually rendered. In my own SPA apps, I very frequently over-fetch to reduce latency. I was hoping there would be a nice compatible way to manage this use case.
I'm not too familiar how this works, but maybe it's enough to query the additional data in parent component or somewhere and it just works.