Holy s…! That deserves to be added here: What's the most brain blasting discovery you've made in co-op?
Haven’t ever noticed that. Mostly coz I send an existing worker to expansion area to wait rather than rallying a queued worker.
Rallying a queued worker to expansion or wherever next structure is coming up is very common in 1v1 where build orders are executed with <1 sec or 0-5 minerals accuracy.