There are so many pages here that this may have been suggested, but I would like to have sort of a scratch pad in HX Edit where, while editing, you could drag blocks to save them while comparing. There are so many Amps/Cabs/Effects/etc, that after tweaking, if you want to try something different and compare, you lose all of your work. It would be nice if you could drag a version of a block to a temporary library so that you could recall it if you want to get back to it.
An alternative/addition/easier to use feature would be to maintain the changes to a particular block type (like Amp) so that if you change the parameters of the one amp type, then change it for another, when you switch back it maintains your settings. It's not back to defaults.
This would be an HX Edit only feature.