I just scheduled 10 test posts to post at the same time. I created the posts in order from 1 to 10, using the “add new” button on top after creating and scheduling the prior post. I find the order they show up in the post list pictured interesting because there is no apparent order to the posts.
After creating the 10 test posts I created I created this one and scheduled it for 5 minutes before the 10 test posts. We’ll see what happens shortly.
ETA – This post posted as scheduled.