How about making the 'open platform options' checkbox non-grayed for Dragon? (to avoid the chicken-and-egg problem)
Today I needed a third debugger, and attempted to use a Dragon with a device in a JTAG chain. It can do it, only one has to either fiddle with the .aps file file with an XML editor, or go through the steps of attaching a non-chained target of the same type, starting debug, changing dragon options and losing contact, stopping debug, plugging into the real target, restarting debug, and remembering to save the valuable .aps file.
It's not that I can't afford the flimsy-flex-Mk2, I have two available. I did however need the 5kV isolation barrier this particular enhanced dragon has.