I noticed that mapbox GL allows vector maps rotation while keeping the labels level.
This is demonstrated, using the keyboard arrow keys, here: //http://bennolan.com/experiments/walk/#17.50/-41.294436/174.772663/-124.0.
This would probably require extensive coding, but would be very cool and useful to have.
While mountain biking with the smartphone on the handlebar I usually keep orientation up, making upside down labels impossible to read.
Is mapbox GL supported at all in OM?
No it's not.