Soft link to other svgs

This is a feature request.

I have a main pageflow diagram, ("FLOW"), and several diagrams that are the pages in the FLOW ("LOGINPAGE", REGISTERPAGE", "REGISTRATIONCOMPLETEPAGE", etc.)

In FLOW I show that a user would navigate from REGISTERPAGE to REGISTRATIONCOMPLETEPAGE to LOGINPAGE. A major issue I have with this setup is that if I decide to change the LOGINPAGE, I have several overhead steps. I have to alter the LOGINPAGE, then copy paste into the FLOW. This gets difficult to manage when the FLOW boasts more than ten screens (which mine does).

I am looking for a way to soft link to LOGINPAGE from FLOW. So changes I make in LOGINPAGE will show up in FLOW without me having to paste them in. On a deeper level, if I am able to define shared styles among pages, so I have fonts, colors, etc. that are soft linked from each of REGISTERPAGE, REGISTRATIONCOMPLETEPAGE, and LOGINPAGE, and these in turn are soft linked in FLOW, I can have a central place where I can manage my styles.

If there is already a way to do this, or a better tool to do this with (I want to keep in in SVG format), I would like to know. Otherwise, I already am familiar with Inkscape and this feature would really rock. Thanks.