The whole "right thrust, down thrust" thing is WAY overblown.

The reason...simple...the effect of it, pretty much BY DEFINITION, varies with the thrust being produced by the engine.

In other words, no matter WHERE the engine is pointed (within, of course, obvious reason...it can't be pointed straight up with relation to the fuse, for example) there is a THRUST at which the forces are nicely aligned. For any other point on the stick, the thrust is not quite enough, or a bit too much.

So...put the engine at 0/0...or 2/2...or 3/2...or wherever. All you're doing is offsetting (or not) P-factor, torque, etc...at one particular point on the curve. Everywhere else, you're STILL out of line.

Where's the "best"? Eh...personal opinion. There's a couple of multi-time world champions who fly at 0/0. A few others wouldn't touch a plane that way.

FWIW, MOST of the "hard core pattern guys" I know view it this way:

They fly for a bit to find the throttle setting that the MAJORITY of their routine will be flown at, and then tweak r/d thrust to as close as they can get to 'perfect' alignment at that throttle setting. That gives them the largest amount of time where the airplane is truly "hands off", they say. From there, they simply manually correct (or mix out, depending) any tendencies of the plane to leave straight and level flight at other throttle settings.