Fixing UVs on skinnedMesh

So in order to tweak UV on a skinned mesh, the best way to do is to tackle it on it's shapeOrig node. 

Let me describe my scenario.

I have a skinned mesh with corrective blendshapes stacking on each other, it looked like this in channel box:

head_bs_target (blendshape node)
skinCluster9 (skinCluster node, duh)
body_corrective_BS (blendshape node)
tweak12

So, adding on another polyTweakUV node will look like this:

polyTweakUV
head_bs_target
skinCluster9
body_corrective_BS
tweak12

As we can imagine, polyTweakUV gets its "inMesh" connection from head_bs_target (head_bs_target.output -> polyTweakUV.inMesh) that means if we bake everything from polyTweakUV by using "Delete non-deformer history", it bakes the geometry itself as well, so it wasn't affected by the deformer nodes even they are still present.

So I duplicate a pre-UV-tweaked mesh, replace polyTweakUV.inMesh connection from head_bs_target to the duplicatedMesh, and then, connect the output to the skinned mesh shapeOrig node, aaaand delete non deformer history. 

Voila! 

Now you have a cleaner mesh with new UVs.