SuiteCommerce Advanced - Request for a "Common" Directory support

I've tried various things so perhaps there is a way and I am not aware, but would like (need) a common directory where I can have multiple reference SSP applications (e.g. My Account and Cart-Checkout) which can leverage the same common directory (since it is very common to load both these references in the same account).  The ability to leverage SSP and the reference models and methods from a single location (as well as CSS and JS libraries in a single location) would be fantastic/needed.  Right now, whenever I modify the sc.environment.ssp file, I need to do it in two