For anyone interested:

Last December I have made the face texture transformer available here in Rendo freestuff. as a proof of concept. I have explicitly left the right to use it and develop it under Creative Commons license. Same had been available as a $0.00 item on Content Paradise since July 2018.

At the time I concluded the method worked reasonably well for transforming V4 and M4 face textures into PE face textures but that although the method could work for full body textures, the difference between the figures in 'cut' of the skin was too large to accommodate with the simple method.

For LaFemme the skin cut looks a lot more like V4's than PE's skin cut does, so chances that you can use the method to make passable conversion morphs of V4 textures into LaFemme textures are a lot better than they are for PE.

I have no time to work this out in the foreseeable future, but the example is there free for whosoever wants to build his or her own product on it.

Check out https://sway.office.com/KwuNb20ciEQbMvJM?ref=Link&loc=play for more information.