I tried something similar last month, and was able to find a set of PID values that would work for a specific chamber temp (I’ve been sticking with 32C for now). However, as soon as I tried a different chamber temp, the control loop would just fall apart. It would probably work in mainline Klipper, but whatever older and/or stripped down version Sovol needed to do just breaks the functionality.
Please take a look at my post PID Controlled Exhaust Fan (Quiet!) - #2 by rpcyan for a more robust solution.