Find Usages is a great feature that I use often.
One limitation that I find annoying is when one do a second Find/search, the new result will clear the first one....
It would be nice to have multiple find usages, that is, one could do several 'find usages' on different objects and the result would show in different tabs. This way one could do a 'drill down' of usages without lose the first object that begun the search. The side effect is that one could over populate the bottom panel with several tabs.
But I could live with that :)