Has anyone tried connecting an externally-mounted fan to an externally vented OTR microwave? It seems a little redundant, but by wife really wants OTR, I really want decent venting.

-If I get an externally vented microwave, can I add an additional external blower to increase the cfm?

-Using the above set-up, might I be able to just use the external fan and not bother with the microwave? This could potentially give me better venting and less noise. Or will I need to run the microwave exhaust anyway?