quikdrawMcgraw said..
The way you guys are describing is different and safer by the sounds of it (easy cauncy) chicken loop on tow ball, connect safety then move the chicken loop from the tow ball to hook on harness.
As opposed to the tether where guys are hooking in to the kite - while the kite is still attached to the tether and then things go pear shaped your attached to kite and tether, in which case a longer tether would be more dangerous by the sounds of it.
There is no need to be be attached to the tether and hooked in to the chicken loop at the same time. After attaching the safety leash, grab the chicken loop and unclip it from the tether while keeping an eye on the kite. If anything goes wrong at this stage you can just let go of the chicken loop. Then simply hook into the chicken loop and launch the kite or launch first and then hook in.
While I'm positioning the kite at the edge of the window I also have a second tether attached to the safety. If anything happens to the main tether (e.g tether breaking from the kite accidentally launching and powering through the window) then the kite will simply flag out.
I have seen kites power through the window in conventional assisted launches too. I don't think it's that much more likely in a tethered launch.
If I don't self launch tethered then I self launch unhooked with one hand on the bar and the other on the chicken loop controlling the power. If anything goes wrong, like a wing tip wrap, then I can simply let go and flag the kite on the safety leash.
No one has mentioned self landing. A tethered landing of course is also a nice alternative in strong winds, especially if you have a kite with a high Y and there are sharp things on the beach. You avoid having to drop the kite hard on the beach or the kite powering up after not quite falling on its nose, with potential to have the line that you yanked on wrap around a hand as poor Nathe described.
Sometimes flagging the kite on the edge of the window doesn't go to plan either in strong wind even if the safety is attached to the upper front line. The kite may not always drop nose down but instead get blown downwind with the potential for damage if there are sharp objects around.
Tethering avoids all this. Again, I unhook from chicken loop first, then attach the chicken loop to the tether. If anything goes wrong, I'm only attached via the safety, until I clip my leash into the second tether.