I've spent a lot of time (waaaaay too much!) in the past trying to decipher NeckFX's unfathomable settings, trying to find meaning in the completely meaningless descriptions of what each adjustment actually does. More through luck than judgment I managed to arrive at settings I was happy with, ones that work in VR but also add head inertia that complements the sustained g-forces from my G-Seat/G-Belt combo. The missing part from my settings was simulating the natural image stabilisation that our eyes and inner ear do so well in the real world. This app achieves that as well as the original Real Head Motion ever did, which is praise indeed.
I've already deleted all of my other NeckFX settings and will be using these ones from now on.
Thanks very much for sharing this @gurkesaft, you've obviously found NeckFX's Rosetta Stone. You've made my driving experience in AC much, much better.
Let me know if the smoothing fixes the issue for you, and I'd love to work on it at https://discord.me/LoPeN if it doesn't!