I wrote a script that will take a Skin Wrap and create an instanced skin modifier of the object is was skin wrapped to. This has allowed me to do lots of things, especially copy and paste weights, because I can have both objects active at the same time. The concept is very simple and you’d probably be better off rewriting the script to suit your environment.
One thing I would encourage any grunt Technical Animator/Artist to do is write your own ‘Weight Tool’. Max’s default weight tool is great, but you will probably be doing lots of weighting until you get into those Lead jobs where your juniors skin (can you write Excel macros in MaxScript??). Maya doesn’t even have a default weight tool so this is even more important for you MEL guys.
Creating your own weight tool has two main benefits: a tool for a customized workflow, exactly for how you like to work. No useless buttons and every button/macro you need is there. Second, it will encourage you to create new Skin tools instead of take the long way around. My Skin Tool has lots of macros I’ve written, and instead of each needing its own UI button or hotkey, I can just integrate it with my Skin tool (I’ve written a Replace Weights for a Bone macro, a Lock Weight(s) macro, some mass copy-paste, grow and paste, and more. My UI has a spot for a custom grow/shrink weight value, etc. Customize it how you want!). It saves tremendous time and energy over the course of even a single project.
The Skin Utilities extracted mesh can also be scaled -1 on the X, delete half, and you can use it to Mirror if the Max mirroring isn’t working correctly or not giving you good results (or if you have a very asymmetrical character, you can adjust the mesh size). You just need to match the bones properly.
BTW the Skin Modifier mirroring is based on bone envelopes- if you have two bones sitting on top of each other (such as twist bones) make sure their envelopes are different, as much as possible, or you will get some strange results from mirroring (actually this was the reason I initially wrote my bone weight replacer…). Restarting Max can also help if your Bones/Envelopes don’t seem to find mirrored versions.