nvidia_367 kernel module options ignored at boot, ubuntu 16.04, /etc/modprobe.d

I want to enable PCIe gen3 operation by using NVreg_EnablePCIeGen3 module parameter. Adding the line

options nvidia_367 NVreg_EnablePCIeGen3=1

to a separate file(named nvidia-gen3.conf) in /etc/modprobe.d directory usually worked(for previous driver versions). But sometimes (and in case of 367.18) the option seems to be ignored at boot. If I do the modprobe manually after boot(previously switching to VT console and rmmod all nvidia modules), everything is OK: nvidia-settings and nvidia-smi report PCI gen3 is enabled, modprobe -v adds module parameter on insert, but systool -vm nvidia still shows no parameters.(maybe module bug?) With the same file present in /etc/modprobe.d I get only PCIe gen2 after boot according to nvidia-settings at least. Is there some stable solution for this? Maybe some other module alias exists(tried nvidia and nvidia-current - no luck)? Or maybe there’s some conflct with nvidia-graphics-drivers.conf in /etc/modprobe.d: for example module alias is added sometimes after my option? BTW adding kernel parameter nvidia.NVreg_EnablePCIeGen3=1 before boot seems to also not work…

Installed nvidia beta driver from ubuntu graphics-drivers PPA.

I actually solved this by just updating initramfs. So the only question left is: why nvidia kernel module not updates sysfs with applied parameter values? Is it some sort of a feature?