Just wondering what I should do about this?  That's as far as the camlok will thread onto my Kriss Vector 10mm

What should you do?  Torque to specified specs and send it.

Is that an HK threaded firearm?  Our mounts in metric were designed for HK threaded pistols, they index the muzzle, and our .578x28 is also a muzzle index thread.  If the part is interfacing where it is supposed to, and the threads are showing that would be because Kriss threaded the barrel a little longer than normal.  

If it is stopping on the threads and never getting to the muzzle face that's a different issue and maybe our part is undersized or the Kriss thread oversized and you have a reason to speak to CS.

Nah nah, that's good.  Don't know why it didn't occur to me that torquing against the muzzle inside the camlok would be fine, stuck in shoulder mentality I suppose.

I use the 9mm CAM-LOK system to mount a .22 silencer on several different firearms.  On a couple of them, to accommodate the
"bare" muzzle thread, I install a 1/2-28 thread spacer designed and precision machined for that purpose  A couple companies sell them.
Best of luck with whatever you pursue.
MHO, YMMV, etc.