Epic DR and Shapeshift

[Side]

So I'm working on a tanky warlock, the word of changing tank all the damage kind. It's a simple setup I seem to find fun so I'm not too concerned about it being good. With that said I'm getting all the fast healing feats and had originally planned on grabbing the epic damage reduction feats too. It hadn't even crossed my mind that they don't stack with the damage reduction warlocks get from their class levels.

Just now I was playing on my wizard and I shapeshifted into a cornugon. It's a nice form to take when you're out of buffs and just need to push through a few enemies before you can rest. I noticed that it has damage reduction built into the form, 10 if I saw it correctly. It made me think for a moment, and after a few failed attempts to get everything working right in jegs I've got two questions for whoever can answer them.

Does the Word of Changing invocation also give a Cornugon form with built in damage reduction?
If so, does the form's damage reduction stack with Epic Damage Reduction feats, warlock damage reduction, or neither?

[Nemni]

The word of changing forms get DR as you can see here: https://wiki.bgtscc.net/index.php?title ... f_Changing
The DR doesn't stack with anything.