In the current (2.1.1) version of AntennaPod, each item looks like this:
Date published · Size TITLE Duration
When an episode has been (partially) played, this changes to:
Date published · Size TITLE Elapsed ———————————————— Duration
With Elapsed looking the same like Duration. So when the user just scans down the left side of the list, the HH:MM:SS fields look all the same, but only Elapsed is a different value than Duration. Could the Duration be bold, whether it is on the left (unplayed) or right (playing) side?