Good news / Bad news!
Good news, this finally got some development time today.
Bad news -- it brings to light a big issue.
Let's go with a rather simple usage case as the example -- you have only 2 preference sets, Imperial and Metric, and have set each detail library to different locations. So now, your Detail Explorer only shows those two wildly different detail libraries.
But here's the problem -- User X remembers that this one metric project had some great details, that they would like to copy over, and convert to inches for an imperial project. So how do they do this? With their preferences set to Imperial, they cannot even see those metric details in the detail explorer. So, they would likely open up that metric project, and edit one of the details. Thinking they can now just save it into the imperial library... only no such luck, they are still locked to looking only at the metric library. So, they change the preference set to Imperial, and now save the detail into the imperial library.
The problem being (!!!) that they just changed the preference set for that metric project to Imperial.
So long story short, as much as this is a good idea, the real puzzler, is how to allow a user to still look at all details in the Detail Explorer, and copy from one library to another.
--J