Sounds like you understand the "
Hotkey Set Action" to me, and it does what you expect.
Sure it's "not fully documented", but ...
http://isboxer.com/wiki/Actions says a
Hotkey Set Action can "Attach a Hotkey Set to a Menu, detach a Hotkey Set from any Menu, or copy Hotkeys from another Hotkey Set"
("New" is not literally part of the name of every single kind of Action ISBoxer has, it means you're going to add a new Action to your Step)
Also, rather than replacing individual buttons on your Menu with 1-Hotkey Sets, I might be inclined to use a Do Menu Button Action as part of a Mapped Key instead.
do they need to be non-overlapping?
No that would make this option pretty useless.
I tested what you're doing just now and it works as expected. With the standard config from the QSW, I added a Hotkey Set with exactly one Hotkey in it set to Escape. Then I made a Mapped Key with one Action in it, a Hotkey Set Action, to set the Standard Hotkey Set, to Apply Hotkeys from other Hotkey Set as my new single Hotkey, and I set the Hotkey position to 12. After I hit my Hotkey, button 12 on the Standard Menu (which the Standard Hotkey Set is already applied to) is then activated via Escape instead of =.
You can double check all of the currently-bound Hotkeys via the in-game Inner Space console if you want. You must set a Hotkey for this in your Character Set (I use Alt+`) and then in the console, enter the command "bind -list". This dumps a list of all the Hotkeys configured with at the time.
Before:
- Code:
[hotkeyLayout_Standard_btn12] [=] Command (Press): noop ${MenuMan:OnHotkey["Standard",12,1]}
[hotkeyLayout_Standard_btn12] [=] Command (Release): noop ${MenuMan:OnHotkey["Standard",12,0]}
After:
- Code:
[hotkeyLayout_Standard_btn12] [Esc] Command (Press): noop ${MenuMan:OnHotkey["Standard",12,1]}
[hotkeyLayout_Standard_btn12] [Esc] Command (Release): noop ${MenuMan:OnHotkey["Standard",12,0]}