Rekordbox - Intelligent Playlists - 'x but not y' features etc.

The Intelligent Playlists function is useful, though it sorely needs some added features to make it shine. 

Right now the playlists have two types:

1. 'include ALL of these'; or
2. 'include ANY of these'.

I would like to see a third option, namely, a combination: 'must include x', and 'any of y, z etc.'

For example, I would like to have an intelligent playlist for my 'Liquid' tracks that included every tune with the key '4A' and '4B'.  I would set up the playlist so it went like this:

MUST

- 'My tag' - contains - Liquid

INCLUDE ANY OF THE FOLLOWING

- Key - contains - 4A

- Key - contains - 4B.

Please do this! :)

Cheers.