fsearch is the best locate front-end for Linux, but sadly, I've got many gripes with it... crappy drag'n'drop, no daemonization to minimize to system tray, closing the app resets the clipboard for some reason (EXTREMELY annoying when you open it to copy a file path), the list is long. Not to mention that locate itself doesn't auto-update the index with fs changes.
Not to detract from your overall point, but the app is not resetting the clipboard. In X11 if you close any app, you lose anything you copy from it. This is because in X11 windows do message passing to emulate a clipboard. Your browser say and fsearch send messages to each other to send data in few KB chunks(yes there's an incremental transfer protocol where you have to support all kinds of irrelevant clients even if the last such client died before the turn of the century) So when one of the windows closes, it's gg. It's a pretty convoluted over-engineered idea when instead a single file ~/. clipboard would have sufficed.
I miss Everything :(