As far as I know, the drivers are ready and we have confirmation that they work well.
Unfortunately, I am unable to confirm their installation method (I do not have a nvidia card.) The best way to install drivers is to ask their maintainer: @Colin or wait for an official announcement.
I suspect (but that’s just my suspicion) that to install the drivers just activate the testing repository and then sudo dnf install nvidia-440
You can also try download and install packages from testing repo manually: Build list - Project openmandriva/nvidia-440 - ABF