Dood the crack hasn't impaired you in anyway, I've seen the TRINITY hood hacking devices just like you've described and as someone else already stated, they suck.
When you set your brush hood alignment, you need to compensate for the armatures rotation and the friction between the com and the brush. As the brush slides against the com, the friction between the two cause the brush to shift inside of the brush hood. This in turn (pardon the pun hehe...), changes the alignment that TRINITYS little "perfect everytime!" tool sets, making it now "wrong everytime" and creating excess arcing which turns into poor com wear and power robbing heat.
The best way to set timing for me
is to install the prepared brushes on the motor after freshly cutting the commutator. Hook the motor up to a power supply of 4 volts and let it run for about 10 seconds. Pull the brushes and measure the distance of the comms mark on the brush face from EACH
side of the brush with a set of calipers. Close to middle, somewhere in the middle, near the middle, or even almost exactly middle isn't good enough if you want an efficient (cooler running), powerful (cuz much less heat), sweeter sounding motor. Next loosen the spring post and hood screw, insert a portion of tool into to the hood about the length of the brush and lightly tweak it to one side or the other according to your measurements. Retighten screws, Reinstall brushes, repower the motor, and then recheck the mark. Keep doing so until the break in mark is dead center with the brush face. After your comfortable with your adjustments run the motor for about a minute or more depending on brush compound to make sure they seat accordingly. Put one last skim cut on the comm and it should be ready to rip!
Again, as stated previously, everyone does this different. If you do it differently from me that doesn't mean either way is wrong. It just means we smoke from different crack pipes!