Add "locked beatgrid true/false" to conditions for intelligent playlists

Hello.

I'm a big fan of intelligent playlists.  All my songs are very well organized using different "My Tag" selections.  That's how I feed my intelligent playlists on different genres. 

The one thing I'm missing currently, is being able to have an intelligent playlist conditioned on "beatgrid locked" true/false.  I personally lock all my tracks when I have set the beatgrid correctly.  For some songs (70's, 80's, this is a hell of a job since automatich beatgrid analysis does not work very well.  So I have to revision them myself).

Reason 1:

I would like to make an intelligent playlist listing all my tracks that have NOT set "locked beatgrid" to identify which ones I still have to check.

Reason 2:

I would like to filter my intelligent playlists (which are now filtered on My Tag <genre>) also "only those that have a locked beatgrid".  As such, this is the only way I can trust on "sync" button working correctly for the tracks I'm playing out of that playlist.