I tried 1_4, i haven't found any known issues while using the normal positions, as well as similar ones, everything seems to working as intended, and i believe the auto knee-bending was a fine addition to the mod. The knee bending only breaks when using non-oral positions (as mentioned), so a solution i would recommend would be if you added a toggle for auto knee-bending, since you would have to go into the settings file to disable auto knee-bending, then restart the game whenever you would want to use a non-oral position. Otherwise, nice work on the mod.
I used Animtools. It's a mod thta allows you edit their poses/animations. You can find it here:
https://www.undertow.club/downloads/animtools.1051/