Hey Mark, hey Jim,
I agree with Jim that while this bit may be good for the long holes for the threaded inserts, for dog holes where fit is important, I would apply the general rule not to use bits longer than absolutely needed. Deflection is an issue easily. Can you repeat the dog holes with a shorter bit and see if the problem gets better?
By the way, if you use the Makita hand router, which is a so-called universal motor, you should know that this is a type of motor that is slowed down by applying mechanical load. The electronics try to prevent that, but the fact that you have no torque at high speed on this type of motor cannot be circumvented by the electronics (for difference between universal and induction motors regarding torque and speed, see here). So on a hand router, the speed setting is usually only the speed with no load. Spindles on VFDs hold the speed independently of the mechanical load (up to the current limit set in the VFD, then they abort with error and, if safety wiring is correct, they interrupt the CNC program. See here for spindle just before the limit 
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