Hi,
There is now a new item in the menu of the TrackManager.
You will find "Select track by length..."
Then you will have a dialog where you can type what you want to select.
if you type 3-10 this will select track that have between 3 and 10 detections ( included )
3- : every track above 3 included
-10 : all tracks bellow 10 included
Note that this will not clear a previous detection, this will add what you selected to the current detection.
Best,
Fabrice