I've been a player since 2013, even though my pc is like really old it has never bothered me to play under 30 fps at all and still managed to have fun, until update 173 (Snipers and difficulty update), this was the update that "fixed" cops reacting faster to the player at the cost of a bit more of CPU usage or whatever. This fix lead to a sudden jump of under 10 or even down to 5 fps since my pc has a low amount of RAM. 
I was wondering if there's a chance of making a mod that reverts the "fix" back making cops react slower as they used to pre U173, but keeping the content up-to-date, or am I lost from playing again and getting to do the secret until I upgrade my pc in the future? (Aka probably never)