I've run multiple trail 5ks and road 10ks since this post, in Pose. Very comfortable in my zero drop shoes, though I expect I have a lot to learn technique wise. Legs feel much lighter afterwards. When I get a little time I'll drop by the gym and run strictly timed 5ks, see what's happening in terms of time and distance.
Update 7/3: Well, I've been working it. Did a
PR run and knocked 2 minutes off my 5k time, cadence is stuck around 165, so there is room for improvement. I am not fast, but I am well above average for my age group. Go Pose.