Hi. My programmer says you need to try starting a new game after you put the patch.
I looked at the patch file and there is no code in it. I did however see in the script.rpy that wincest should load, but it doesn't.
make sure the patch file is is name incest_test.rpy (for me it downloaded as copy of incest_test.rpy and needed to be renamed), then put in in the location\game folder and it works on a new game.
Yes I did that as soon as I downloaded it. However, when it still didn't work, I opened up the file and saw no code written in it.
Doesn't need any, it works based on other code checking if the file being present.