I have mine angled so when you normally look at them a third of your elbow is in the mirror in normal riding position, then just tuck your arm in a bit and you should see what's behind you
Bike mirrors are in the same class as tits on a fish, chocolate fireguards and brake lights on a submarine.
Just taken mine off and made my own for the r/h only.Just got to find the right lights to replace em.
There are companies that make raiser for them so they clear the elbow slightly better, it's just a machined block essentially
I bought my Blade in April this year and after having a Ducati, the Blades mirrors are fantastic in comparison! You can set them up to be effective but takes some time and adjustments and personally, don't see the need for extenders. Ducati's were just plain useless......