Spending time looking up,  with a quick check down to see saw progress, is a preferable thing. 
Lots of people watch their saw continue in the same plane as they started the cut,  rarely looking up at the top.  I can be guilty of this, if not being vigilant
I like to smack a wedge,  and look up,  smack,  look,  smack,  look,  when wedging anything dicey. 
Also,  timing a swing of the ax with the tree movement is a finesse part of wedging, imo. This might be to sync with wind,  motion imparted by wedging (rocking back and forth,  or a wobble, like with a dead,  slow- tapering tree, conifer or otherwise) or multifactorial.