Mirroring a joint corrective morph

Hi, I've been struggling for couple hours, now I am here again in search of answers. 

All went well for the JCM I created for the left side thigh; I want the JCM to activate when the thigh rotation side-side is active. I create the morph in Zbrush for the left side, make the morph a type modifier/pose, then open property hierarchy to find 1st stage controller of new morph and drag and drop the Left tigh side-side rotation pose I need to correct and it works all well. Up to this I think I'm doing everything okay

The right side is now the problem and it has to do with the attributed sign of the right side it seems (Left bends in (+) and right bends in (-)). So, I grab the morph I made for left side­ > morph loader pro > hit the morph mirroring option to "swap x axis" (this I'm not sure it's the right option). The morph comes out okay for the right side. In property hierarchy, I do the same as the left side but for the right tigh and now, the resulting JCM is kinda inverted. I want the morph to go from 0 > 100 when the joint (R side-side bend) goes open 0 > -50. As of now, my morph is applied (+) when the bend closes -50 > 0. 

Is the problem with the right side in property hierarchy or when I mirror the morph in morph loader pro? I think I would need my morph to invert the sign, so instead of gradually applying from 0 > 100, it would applies from 0 > -100, as all Right pose transform do. How can I do that?

Any alternative?

Big thanks