You know you could have used a 90 degree chuck buddy. Or better yet, an angle grinder to make it a friction drive from above.

angle grinders run really fast, and even those with speed control just lower total power, not increase torque.

it would have made more sense to just mount the motor and the planetary, but I think the planetary is important here.

It's got 2 miles of range, adding those complications would likely eat up a lot of the range.