So first off, important context - I'm using these awesome film sims exactly as I do on Fuji, for no-edit JPEG shooting. This is mostly irrelevant for video shooting that's still going to be graded afterward. With that in mind...
I have a question on the logic behind the knee settings. I've noticed in the ~10 profiles I've tried out, all but one(forgot which one, but it had auto knee) of them have knee settings that result in them not coming even close to hitting full white value. In fact, there are sims that use profiles that already top out at 100 IRE, but still have aggressive knees applied, which ends up cutting max luminance off way, way under the actual 255 white clip point.
So I'm just curious what the process has been for creating the knee settings. Knee is intended for profiles that max over 100 IRE as a way to have control over how that data is brought under 100 IRE. I'm guessing it's about matching the dynamic range and highlight roll off of the film stock, but at least for no-edit photo shooting, this isn't a good way to go about it because it leaves you with images that will never hit max brightness no matter how brightly they're exposed.
What I've done for my own photo shooting is to set zebras at 100%, then go through the profiles and adjust the knee slope until zebras appear (in the case of profiles that max at 100 IRE like Cine2, is requires a linear slope/knee off, i.e. +5). This yields better dynamic range and images that actually hit full brightness, while still maintaining the most knee possible from the intended knee point to help highlight roll-off.