Electrics and governor mode

I've got myself a T-Rex 450 SE V2. The user's manual and the
experienced guys say to not use the governor mode which the ESC
sup****ts. The experienced guys say it's because the ESC gets too hot,
while the manual gives no reason at all.

The heli flies very well with the throttle at full blast all the time,
but I can't help thinking I might get a minute or two more flight time
if I reduced the head speed a little.

Does it make sense to try with the ESC in governor mode, or would I
risk something really bad?

What other things are there to think about when flight time per
battery is the subject?

The ESC has different "timing" settings. It is currently at "medium".
The manual states that "high" would cause more battery drain. Does
that mean that "low" would cause less battery drain?

There is also a setting for "throttle response". Would that impact
current draw noticeably?

I realize, of course, that extending flight time will reduce motor
power, but since that is currently plentiful, a small sacrifice might
be acceptable.
-- 
RoRo