I started to port my patches to xwax 0.7 (beta1) with the highlighting of played tracks.
Basically this patch provides a simple highlighting of played/loaded tracks in the record selector of xwax. You will see two new crates named “Played records” and “Loaded records” which are automatically managed by xwax (see screenshot below).

Once you load a record to a deck xwax will mark the record as “loaded”. You can continue to skip through your record list and each record you load, will be marked as “loaded”. A record gets marked as “played” when the previously loaded record was loaded to another deck.
You can toggle through the 3 states (not highlighted, loaded, played) with the DEL key.
How do you get it? You can pull the 0.7+playedtracks branch from my xwax repository @ githib. Github should also offer you a download button to get the source code.