when having multiple instances of PL/SQL open, which session decides what is places in:

(1) the Recall SQL Dialog
(2) the (Re)Open Files menu
(3) the Clipboard
(4) the state of the windows, and which windows are open, to be re-opened. This is especially weird, because since v14, and now v15, the interface reopens files, even though I'm not able to close down the application without closing all the open windows

Just would like to know the rules, because, after 13 years I've been using your product, I still can't figure it out, and especially the recall function, which I use a lot, saves me a lot from saves temporary scripts (which can't be found through (Re)Open files)

The Recall buffer and Clipboard will be updated by all instances of the same version.

The recent files and window state will be updated when PL/SQL Developer exits, so the last instance that is closed will "win".