Just an observation: My woodworking shop housed a Dewalt radial saw that I often used with a dado head, a 6 X 30 belt sander and I made frequent use of a high powered router swinging bits as large as 2". My dust collection system was a wet/dry shop vac with a standard hose and an adapter to a i" hose for the router. The standard hose fitted dust ports on the saw and sander. I think I collected 80-90% of the sawdust created. I doubt that the capacity was anywhere close to 400 CFM. But, the critical parameter for effectiveness in a small scale operation is air velocity not volume per se.
On another topic: A slab of machinists wax is good to have around. You can use it, with rapid traverses, to proof a tool path program and the resurface (or remelt) it for the next job.
EM
