This response isn’t free. (Invoice will be faxed)
What I really wanted was just one “device” to mess with, and more importantly, only one file created from the workout. Keeping hours, “miles” and tss logged simple. Otherwise, I woulda just used TR on my bike computer while on Zwift like mentioned.
so the hack for your 4x12-min sweet spot intervals is to enter each 12-min interval as recovery, and then you can specify free mode? It wasn’t clear from your screenshots, and I haven’t used Zwift’s workout editor.
Probably easiest thing to do is create the ENTIRE ride as a “free ride” then add text prompts at locations within…
This quick example is from https://www.zwiftworkout.com/, but I assume that the native Zwift workout creator tool would do the same???
Sure, but I do have a mobile phone and I don’t have a bike computer, so in my particular weird case the marginal cost of my solution is zero.
Plus I now pay annually for Zwift, so it only costs me one twelfth of what it used to. 
In my second pic you drag and drop from the stuff on the right, it then has spots that pop up to enter time duration and power target (in watts or as a % of ftp). Really quick and easy to make, only bummer is you can’t do it on Apple TV or (I think) iPhone, just iPad or PC.
Wouldn’t get “laps” doing it that way to see/compare intervals on TR or Strava.
Thanks. I gave up years ago and simply do all intervals, inside or outside, using my bike computer. So much simpler having only 1 user interface. However I do bast majority of riding outside. YMMV.
The whole point of using the method that @RMS138 discovered is to be able to perform a workout on zwift using the terrain to modulate your power while at the same time, have the ability to have laps created automatically and have the timer for each interval,etc.
The way you described wouldn’t add the laps, so kinda defeats the purpose of using this method. 
Are you sure that free ride in a workout is terrain mode? I’ve done a FTP test a while back and the 20mins part was free ride. But i was still in what i call “resistance/slope mode”. Or can you select different kind of free ride options?
That was my thought, too.
You can use the following “hack” explained by @gpl in this video if it doesn’t work for you i guess?
I still haven’t tried the method @RMS138 posted, so i have no idea if the freeride option works or not. (as in have zwift activating the terrain changes when riding in freemode).
But if it doesn’t work, all you need to do is follow the solution on the video and i guess it should work after that?
forgive me if i’m misinterpreting, but if you want free ride sections without it reverting to sim, you can edit the .zwo and add flatroad=1 to the section. i do 2hr freeride workouts where I might be doing stuff like vo2 intervals with varying rest times so I don’t like being bound by a pre-programmed workout
<workout>
<FreeRide Duration="7200" FlatRoad="1"/>
</workout>
Like I mentioned, I’m giving the workout I built a try tonight so I haven’t fully tested it. But when I was doing a similar 4x10 SS on Tuesday I had the SS intervals like normal and the rest intervals in free ride. I was in a rolling part of Sand and Sequoias when I went from a SS interval to the free ride rest and it definitely was following the terrain.
I’ll see for sure tonight but I don’t see why it wouldn’t work.
we actually want the opposite. We want to add 0 instead of 1 because we want to have the ability to follow the terrain while in a workout.
Perfect. Next time it rains i’m certainly using this method to do my workouts on zwift!