Jake brakes work by opening the exhaust valve sooner in the compression cycle and reducing the amount of energy transferred to the crankshaft. I am not sure how introducing a throttle blade into the intake tract would work although I get your line of reasoning.

We ran jakes on dozens of trucks for decades and never had any issues other than breaking wiring connectors when working around the heads. I think they are very reliable at least in a heavy duty application. At least on a Cummins. Not to sure about those crappy Detroit's and Cat's.