As professional models become more detailed the need for a function like AutoCAD X-ref becomes more important. When will Trimble add this functionality to Sketchup Pro?
You’ll know when it happens. Until then, no one who might know is at liberty to say.
In the mean time check out TIG’s plugin.
Note that none of these plugins lowers the file size of the master model; the “linked” model will be embedded as a component, unlike how AutoCad handles references.
Who is TIG?
TIG is a regular forum poster and developer of many SketchUp plugins and extensions.
If the Model is imported as a component then, as you stated the file size will increase and will not help manage large models. I can see using the CRO plug-in in multiple user environments.
@TIG plugins author extraordinaire.