It's been a while since I played with it but I used version 04 of the software you linked in your first post in the reddit thread. Which I found by changing the URL to:
http://olli.wtf/vive/so it is this one:
http://olli.wtf/vive/vive_mouse_v04.zipSo I run the config app I think and then I think I chose the option where you put the tracker in the corners of the screen. Being careful to do it in the order that it wants them being done, top, left, right etc, whatever it says.
Pretty sure that gives the best calibration rather than the aiming one.
I also had to adjust the X axis or Y axis value or something by 90 or -90 degrees so that it wasn't aiming straight down.
I had a python program that could pick up the pogo pin keys, there is a library for it. I had to manually map a key for a game but I was going to make it scriptable.
I had it working on a 86 inch tv and was like 4 feet away or something and it was accurate.
If you want I can dig out the gun and setup the light houses and do it again. Record a video or whatever.
You are right about the hyperkin gun though, the iron sights thing isn't good.