Big apologies for long delay.
Here is a scenario... There is an app called Pebble Locker that although designed for a Pebble watch, allows any BT device to act as a trusted connection and automatically disables PIN lock. If no Pebble or other trusted device is conected, PIN lock returns. (Unfortunately it doesn't work with pattern lock or fingerprint scan). The idea is that if you have a separate device near the phone, it lowers the barrier. If you leave the device, the barrier rises again. I'm hoping the Fetch would work for that as it would almost always be in my pocket or nearby.
Of course, it would be better if it was something built in to HTC devices. Some time ago I stumbled across their SDK and it seems to be pretty powerful but I'm not a programmer so...
-Separate note: I've seen some discussions that the KitKat update on the HTC One's breaks Fetch. Not too many confirmations, but no denials either.