Bowmaster,
I don' t own one so I can only speculate here.........but the reason most (heck all) target archers shoot simple and solid rest designs is precision and repeatability from shot to shot. All shots must be consistent. Lizard tongue and other solid launchers on solid mounts are the standard fare.
I would imagine the Whisker Bisq. by design to have too much variance from shot to shot to be " Spot" accurate for true Target applications. The nature of soft bristles and how the shaft and vanes propel through this material just doesn' t spell consistency to me.
Probably plenty consistent to get the job done on game........has to be they sell a ton of them, but not consistent enough for really getting down to fine pin-point accuracy.