shortcuts for stamps have been suggested before, and dismissed (viewtopic.php?p=102461#p102461) on the grounds that stamps are dynamically loaded.
This is actually one of the biggest reasons I still use Bluebeam Rev 20 Extreme for work, (in addition to PDF XChange), because Bluebeam has a decent implementation of hotkeys for what they call "tools" (equivalent of stamps).
There is one toolbox that is numbered, and you can press a sequence of numbers to select that tool. For example, I have 2000 tools (most of them placeholders), and can type "100" and select a certain stamp or "5" or "304" or whatever. I literally have thousands of slots I can put anything I want in. And these tools are also dynamically loaded from file.
An even better implementation would be each stamp collection can be assigned a number (any number). And you type that, prior to whatever number of the stamp in that collection.
Mockup:
Stamp collections are assigned numbers, but you can change them, and order them how you like (also another feature request).
In the mockup, the "Test Stamp" would have the hotkey "502" (when you're not typing in a textbox or something).
