Enter should emplace ornament/element from Master Palette
As with the regular palette in workspace (when an ornament/element is selected, pressing enter from keyboard will emplace that element at current location equivalent to double clicking it), the user should be able to do the same behavior while in the master palette. The fact is that selecting the category in the master palette allows the user to press 'tab' and then cycle through elements/ornaments using arrow keys, and with this the user should also be allowed to press 'enter' and have that ornament/element be utilized exactly as with the palette in a workspace, but as it currently is, double-clicking and dragging seem to be the only methods of entry from the M.P.
Consider making this uniform in function: it makes sense. As a matter of fact, this is on the brink of being considered a bug rather than a suggestion, as it could be argued that this is expected behavior. Entering into the Master Palette quickly and being able to -- with the keyboard -- enter a desired ornament would very much facilitate certain actions during note input, etc.