Nice to see another KFlop user on here!

I'd personally go for a belt reduction, but if trying direct mount is relatively easy, it's worth trying. Whether it will work, will most likely depend on what you try doing with it.
The worst thing I would expect to highlight any lack of torque, would be during drilling, especially when you try retracting the drill, when you're fighting against the weight of the head and the drill still trying to dig in.

Regarding the EM drive being noisy, have you ran the autotune function?