Hello Martin! I am not totally sure i understand your system, but the main reason seems to be the dust extraction. Why a square base? for hand routing, the square base works well for routing exact widths dado's, and and such. Then, you would vary the edges to different Dept's to the bit. You can turn the base, and widen the hole by 1/16 th., or 1/8, Or 1/4 in. bigger depending what you use. By the way, Label, or you will regret it. You can also make the square hole, and make different inserts to be able to hold collars, or use a square hole for dust, or what ever. The base must be perfectly centered to the bit opening, as well as every insert. I hope this may help. If the super dust collector router has a fan on the motor to draw air through that is more efficient that the other router, It may be all in vain. I hope i helped, Tell me how it all works.
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