I'd take the right position, maybe a bit further left, say 2cm, so the spray mostly points into the pipe. You might even point the nozzle straight down into the pipe towards the manifold.
The left nozzle position would likely lead to a large percentage of the droplets hitting the outer walls of the pipes creating more of a wall bound fluid stream than mist.
Water vapor does little for you power wise, it actually costs power. You need it mostly as fine fluid droplets in the cylinder.
For methanol this is less of an issue. Most will evaporate even just hitting the hot inlet valve. There has been research done on comparing ethanol port injection vs direct (in cylinder) injection regarding charge cooling effect.
http://www.aquamist.co.uk/forum2/vbu...eferrerid=6624
They found that much of the ethanol seems to evaporate hitting either the inlet valve or the cylinder walls (cylinder, head and piston crown) before the intake valve closes. It rather cools the metal than the inlet charge and does little to raise the knock limit by means of in cylinder charge cooling. It still raises knock limit due to its chemical properties aka high octane number.
That can be a good thing, too, say for a heat sensitive motor lacking piston oil jet cooling or a rotary engine.
One more suggestion. Mount nozzle threats for both positions and compare what gains you the most power after ignition tuning. You will find that the ignition advance requeirements will be rather different for the two positions. The position that needs the most ignition advance to restore full power got the most water mist into the cylinder. With the engine being out of the car this is very easy to implement.
The more methanol your mix contains, the less the nozzle position matters.