Having trouble mixing up the interpolation grid and drawing substitutes

Hello,
(using harmony 15) I reached the stage in my rig where i want to set up a master controler to rotate the body and face of my character. I didn’t want to overload it with envelopes, so some of the elements like the mouth and the nose are done with drawing substitutes (I don’t mind the hard transition) except once I used the interpolation grid script, all the values are saved and it moves well, with the exception of the drawing substitutes, they don’t change at all and keep the exposure from the previous pose. (for example if turn the head to a profile, she will still have her front nose)
Any idea if I missed a step somewhere or if there is a workaround?
Thanks you :slight_smile: