in general lnav is very nice being enroute
In general we use it from departure to landing with the exception of radar headings
The LNAV just follows instructions from the source, be it VOR or FMS.
enroute its sometimes nice to switch in hdg when there is a major course difference between two fixes on your route . leaving lnav engaged would result the ap flies exactly overhead the fix and then goes into a full 25 deg bank - doing it by hdg you can start the turn some seconds earlier and turning the knob slowly smoothens it out
Wow, havent heard of this procedure, LNAV will calculate the required lead for starting the turn, plus at altitude it knows it is restricted to half bank. Our autopilot doesn't like humans trying to second guess what it should be doing.
Mutt