Wondering if there's a common pattern for an interceptor which stops a handler from being called

Looks like you could empty the :queue from the context... something like that perhaps.

@olivergeorge I've never used the technique. But certainly possible as you say.

An idea - when -deref is called on a sub somewhere where reagent.ratom/reactive? is false, it should issue a descriptive warning, maybe with a link to the relevant documentation entry. What do you think?

(I'm assuming my understanding of what reagent.ratom/reactive? checks for is correct)

+1, to ensure the deref of a subscription is always inside a reagent component. There should also be a way to opt out of that.

Find re-frame events and subscriptions easily => https://github.com/borkdude/grasp#finding-keywords