Thanks for getting in touch! Sadly I don’t think there’s a good answer to this question. There isn’t any event like this that you could hook into a subscription, but you could theoretically pull the tasks and use the filter to see which ones are queued as a workaround that’s probably not ideal.
Maybe subscribing to the
Deployment Queued event would get you part of the way there? This could you give you a bit of a round about idea of when the task cap has been hit.
What I’d suggest going forward is to raise this enhancement idea up on our UserVoice site so we can gauge community support and prioritize implementing this.
I hope this helps in any way! Let me know what you think or if you have any further questions going forward.