It's not dissimilar, Mike! I think the only major difference is that I'm more of a structuralist, so I use the storyform/PSR to outline the 'moments'. However, I'm never wedded to the outline. I tend to work in a very chaotic, freeform way. I find I get bored if I just follow a roadmap the entire way, so I only use the storyform to loosely outline the 'moments' and then write without even thinking about it.
An example from a First Draft I completed:
The initial outline has an OS sequence reading like this - "Alex chooses to hide the truth from the others. Tessa is accused of stealing at a gas station because of the YouTube video, leading Alex's lie to be uncovered. A rift forms amongst the group, but there’s no other choice but to go on — even if the trust has been eroded."
The final sequence, which came to around 6 pages, became much more than just the OS elements:
The opening beat is Tessa (the MC) in the gas station. Some dude keeps saying he knows her. Despite her insistence that it's not her, he won't give in. Then comes the OS element -- the dude has a YouTube clip that shows Tessa beating up a couple of guys (OS/MC Problem of Cause). After he creates a scene, she pays for her stuff and flees to the car.
Second beat is where she tells the group about the video. She discovers the IC knew. That brings in the IC's points -- he didn't want to freak everyone out (IC Counterpoint of Worry). Then the RS kicks up -- the IC could have prevented this sooner (RS Issue of Ability), but he just didn't want to (RS Counterpoint of Desire).
Third beat (which wasn't in the outline) is that the dude comes out of the gas station, and Alex loses his temper for the first time (IC Concern of Preconscious). Tessa comes to take him back to the car, unhappy with how he's acting (RS Concern of Being).
All of that leads into the next sequence, which is primarily RS-based with MC/IC elements and follows on from that argument. Obviously, it's a first draft and it's messy as hell. But the process is the same for any first draft I write. It never comes out the same way as I write in the outline because you always find a moment where you think 'This would be a perfect moment for the IC to do that' or something. Which is exactly what you found, also.
In fact, the screenplay I'm writing at the moment has a much longer first act than I had anticipated because in the outline, I had prioritised the RS; but in the screenplay, I found much more to work with in the OS and MC throughlines than I had expected, and the IC/RS got pushed back slightly (a lesson learned there: never underestimate the amount of anger I have toward the outdated class system we have here in Britain).