Add 'manipulation' touch-action property?

Hi,
I'd like to propose we add IE's 'touch-action: manipulation' [1] property
to the pointer events specification.  We've avoided the Microsoft-specific
properties because they're explicitly out of scope for the working group,
but I think we can word the definition of 'manipulation' such that it's
within the scope of the group and consistent with the existing language.
 In particular, how about something like:

manipulation: The user agent MAY consider touches that begin on the element
only for the purposes of panning and continuous zooming.  Any additional
behaviors supported by 'auto' are out of scope for this specification.

I'm happy to go into why I think this is important, but my biggest reasons
out out of scope for this group.  Instead we can focus on:
 - improves compatibility with existing sites (manipulation seems to be the
most commonly used of the non-standard properties)
 - acts as a nice shorthand replacement for the more awkward 'touch-action:
pan-x pan-y'

Alternately, I'd even be content to spec 'manipulation' as a synonym for
'pan-x pan-y' but say that user agents may choose to associate with it
additional semantics that are out of scope with this specification.

Thanks,
   Rick

[1] http://msdn.microsoft.com/en-us/library/windows/apps/hh767313.aspx