FOK one thing you will notice is the 46 AX comes with the #3 plug in the box, I did my break in with that plug and it worked fine.
one thing I found is the engine ran a little better using a #8 plug after break in, and has a smoother idle as well.
the #3 tended to burn out faster even after the break in was done, so I switched plugs and it seems to run better could be just mine but the #8's are a little more expensive by a couple of bucks is all.
when breaking in engines plugs tend to burn out faster untill the engine is fully seated, the metal shavings can foul the plugs rather quickly so don't be surprised when yours does as well.
read your manual and follow the simple break in procedure and you will have a great running engine for a long time to come, mine is a great little powerhouse.
I like the remote needle on all of my planes that have them, there doesn't seem to be any perceptable performance difference, and when your fingers are further away from the prop the better off you will be.