Last week I asked Jeti a few questions via their website, to their credit they replied to all within a few days.
One of my problems was that I could not get the double button press in the DS-16 jetibox emulator to work. The answer from Jeti is that they have to be held down for at least 2 seconds, it felt like longer than that but it does work and then the screen message changes to say it has been successful.
Why a double button press? Several actions such as re-setting the GPS origin can be done by a double button press on the relevant menu item. GPS origin is important for zero-ing your position for values such as distance (from you), relative height (above starting point), and so on.
GPS origin can be re-set by plugging the MGPS second cable into a spare channel and switching it, as long as the servo pulse passes centre it resets the origin. However I am already using all 15 outputs of a CB200 so I have to use the jetibox emulator to set the origin. I fly that jet model at 4 different airfields and it is useful to be able to re-set the origin to that airfield at the start of a flying session.