Hey LilSkittle!
I tried reproducing the issue with the steps you've provided, but I wasn't able to take any fall damage with NoFall enabled. It seems to be something specific to your setup.
Can you share any other details or configurations that might be affecting this? Please note that as of Wurst 7.44, it's possible to pause NoFall when you are holding a mace. When this feature is active, it says "NoFall (paused)" in the HackList. Could you double-check that it doesn't say that when you are taking fall damage?
Also, does the server you're playing on have any kind of anticheat that might be blocking NoFall? Let me know so we can figure this out!