HVAC vent baffles

I got a bee in my bonnet about adding a psuedo zoned HVAC mods to my single zone conventional gas and compressor system. I know A that you can't just cut off a lot of airflow as it may freeze the A coils. My plan is using cardboard circles with a copper wire protruding from one edge (to articulate with drilled holes on round duct) and a servo body mounted into appropriately sized cutout in circle baffle. The design is essentially like a automotive throttle body. I've seen designs where they actuated louvers, which I see as problematic... They are very high friction, they rust .. etc... Hence butterfly. The horn of servo will be epoxied 180deg around from wire in hole to inside of ducting with JB 5 minute. I figure the tight space may present a challenge... It's 7 inches.. I think. I may need to use a flex drill bit, but budget prompted me to another idea. Use a toroidal magnet and stick it inside, wire can go in center void of magnet. MCUs with Dallas 1802bs are about the apartment. Sound feasable?