Originally Posted by Globalstar66
Maybe read the rules thoroughly before making these kinds of bold statements, or enlighten us as to where you see it's not allowed.
Read the Annex from 2015, the only digital/electronic equipment allowed. That should help you.
Also ask yourself why NOT one single other shooter uses one perhaps? Spirit Level means analogue where I grew up and not electronic.
The rules of FT have always been pretty open to allow advancement but as far as I know from the people involved other electronic equipment is still under debate on if it will be allowed. The best person to ask is probably Bri Samson.