Use short lag bolts. Measure your plywood/drywall/bracket and use lag bolts that wont protrude beyond that. Then you wont have to worry about punching a hole in the conduit.
This bit of advice is coming from a guy who once lag bolted a bracket through a pocket door. TV was mounted solid but they no longer had privacy in the bathroom :).
Avid Stamp Collector - I really love 39 Cent Stamps