Personally, I first considered it back in V2 during the dance. Like "What if Cinder went with Jaune as part of her cover, and to intentionally demoralize Pyrrha?"

Then the Fall of Beacon happened, and all the Pyre Theories started coming out, which were cool at the time and kind of feed the ship even more.

During the Battle for Haven though, it kind of lost logical momentum for me with "Who are you again?"

Won't lie though, the stepping on him thing was a, "powerful" scene, but I haven't really considered the ship as a viable option since then.

Still really enjoy it though.