But being too much focused on, is maybe a risk ?
Which is where audio-out and a helmet headset come handy, audible announcements will simply cut down the time required to decipher the screen info... in fact you'll won't even need to look at the screen very often...
Further is Satnav only an
assistant, traffic/road safety comes first, always... if the situation doesn't allow, cancel the exit/turn, let the unit recalculate and come around... (already enough BD cagers around doing stupid things on busy roads/intersection cause their satnag tells them ;-) )
Before using it on the motorcycle, I first practised in the car with the Garmin, going places like work, groceries or the GF's family, just to get used and accustomed to its haptics audio, and screen info...
Yeah, over me playing with the GPS for going to her mom's the damsel did express her opinion that I obviously "must have lost it", but later during a 2 week motorcycle tour to/through the south of France she then admitted that those seemingly stupid training-runs weren't so dumb at all...
And since smart-phones normally aren't waterproof, you'll need to consider some containment/weather protection as well, which might impact your intended place and/or type of installation...
In daylight conditions the screen might not be easily readable, thus some form of screen might proof useful too... at least a matte, non reflective protection foil...