At a recent UFC event it struck me that a fighter called Edson Barboza effectively used an oi tsuki/jun tsuki in a very similar manner to how Iain teaches it when applying kata. Namely throwing body weight into a punch and allowing the trailing leg to step through and "catch" you after the punch has landed. Rather than stepping and THEN punching.
Approximately at 1:18 of this video for example...
A popular fight analyst called Jack Slack commented on this in his latest podcast and how this was a good example of how a stepping punch can and should be used.
I always like to find cross overs between the bunkai world and the combat sport world as the combat sport world offers visible and tangible evidence of efficacy where, on occasion, the bunkai world does not. At least not in such a prominent way.