Disable xrefs before file load

Hey all,

If you have a scene that has a lot of xref scenes connected to it, I'm wondering if it is possible to disable these before the master files begins loading?

My dream is that you would be able to save the scene with all of the xrefs enabled (therefore not having to wait for the files to unload before you save) and then when you open the master scene, all xrefs are disabled and only the content contained within that scene loads, saving load time.
The user could then enable additional scenes if they so choose.

I've done a bit of experimentation with adding a "disable all xrefs" script to the scene callbacks but couldn't get the result I wanted.

Am I asking the impossible?