Lower than average fps or fps drops with SK installed on some games

Big fan of SK and I used it for a lot of games. For game specific fixes, hdr tonemapper, an actual good framerate limiter, nvidia reflex, etc. love it BUT… with a lot of games, seems like mostly square enix games that do this, but also other open world games or unreal engine games, I get a lower than average fps or fps drop when turning the camera in populated areas. It gets quite distracting at times and i usually just end up just uninstalling SK for said game when it happens, and just going without the extra bells and whistles in favor of smoother performance. I have older hardware, 4790k - DRR3 2200mhz. I suspect SK works better with newer/better CPUs or RAM.
Anyways, I digress, what I am wondering is what is the cause of this bottlekneck with SpecialK and can we fix it? Is it possible to configure SK to be a little more lightweight? I have seen a couple posts describing similar issues, but can’t find much other info and haven’t had any luck tweaking SK’s settings. I can’t be the only one with this issue.