Currently if you arm a toolbar button, do a bunch of work, then hit undo, the toolbar button unarms. It's a bit of a pain to have to go back and rearm it to keep working any time I have to undo. I feel like it should be default for an armed toolbar button to survive an undo, but if we have to make it a preference then it should definitely be there.
The other thing is that when you have a toolbar button armed, you lose the standard cursors. So for example, I can't hover my mouse over an item edge and see the "Trim" cursor or "Fade" cursor to know where to perform those functions, because I am stuck with the "Pointer with an A" cursor for the armed toolbar button. I understand with some things you should probably be able to tell that you have it armed via cursor, but for a lot of other things, it just means people have to guess while performing other edits with the button armed. So a global preference for "Use armed cursor when toolbar buttons are armed" makes a lot of sense to me, or alternatively a checkbox in the menu editor per toolbar button, depending on if you want the armed cursor or not for that function.
Vote for keeping standard trim/fade/item vol/time stretch/etc cursors here: http://forum.cockos.com/project.php?issueid=2428
Confirm "undo" survival bug here: http://forum.cockos.com/showthread.php?t=57198
Allow armed toolbar buttons to survive "undo" and preference to keep standard cursors
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