OK then, if it is that simple, I might try it myself. What do you do when you get to the point where the beginning and end meet?
Do you leave the strip a little longer, shorter or cut it exactly to length? When do you pull the tool from the groove? Etc.?
My lockstip was longer than the beading.
When I get to the end I trim off the lockstrip to sit flush with the other end. If it happens to be a bit shorter then no big deal. There is still enough pressure on the window to keep it in place.
When you get to the last 1 or 2 inches you can take the tool out and press the remainder in using the end of the tool.