Here's a different idea:
Consider the regular Contacts instead of the Contact Pros. The Contact's highback has good flex for the park, but the base is much more responsive because it has a lot less EVA dampening zones (just under heel) than on the Contact Pro (all over the entire base).
The Force is also a great binding for all-mountain and park. However, some people have said it's a little heavier and I know for sure that the toe strap ratchets are difficult to release, as I have them.
I also have a pair of the DLX bindings, which I'm using now but I improved them by putting the Force straps on them but kept on the DLX ratchets, which hold just as good but release a lot more easily than the Force ratchets.
The DLX highback has very similar flex the the Contact highback, and I use these bindings both for all mountain and park, just like you plan on doing. The softer highback has not been a problem for me whenever I've done powder and ice on steep terrain. They're actually really responsive when I go heelside.
So, with all this in mind, you might be best with the Contact bindings. I know, they look like they're just meant for park because Scott Stevens rides them, but they'd definitely work just as good for all-mountain.