Hi David -
There are some long term goals to better enable this sort of thing, though it requires quite a bit of investment .. so it's a bit far down my list at the moment. However, something you may find useful is that NCrunch stores the custom engine modes in the .ncrunchsolution file, which is also the file containing solution level build/test configuration for your entire team. If you ensure this file is checked into your source control system, you should have the engine modes shared.
You can find some more information about NCrunch settings files in this thread:
http://forum.ncrunch.net...s-when-code-changes.aspxCheers,
Remco