Hey flyingclint--glad I can help--even a little.
Like you, I'm a professional editor/motion graphics designer/cinematographer using (mostly) Canon platforms. Ya, the Inspire has a fixed 2.8 iris, so we have to compensate for iris adjustments in other ways. When I read the settings from those LUTS I got from Neuman Films, I saw that he recommended that the shutter speed should be set at 60, and said: ya right---how? On the beach? LOL. Just yesterday at the beach in LaJolla (San Diego), the lowest shutter I could work with to not have everything completely blown out was 400.
So-----I'm trying to track down a variable ND filter that we can work with (ie: mm size, weight, thread pitch) and when I do I will post about it immediately.
As for what you are asking about the manual control of EV--this is what I see it as--and I'd love to be corrected if I'm missing something: you can't "directly" control EV. It shows a result of other adjustments. ie: what you are achieving with your various settings of ISO and shutter. When I spin the shutter dial (upper right dial on the controller) or adjust the shutter in the app, I see the EV adjust in the app. Make sense? You adjust EV by adjusting other things. Please correct me if you learn otherwise.
Ultimately I am working to get my shutter to 60 all the time. In a perfect world (haha), I'd keep my shutter at 60, and adjust a variable ND as needed before takeoff. If I got up in the sky and wanted it different, I'd be fine with adjusting my shutter to 100 or so, and if I wanted it lower I'd have to land to adjust the ND. Not a big deal when you need to get the right shot the way you want it.