engine braking and brake life

Engine braking essentially works by closing the throttle body thus starving the engine of air and creating a vacuum in the combustion chamber.
A negative side-effect is that the vacuum pulls oil from the crankcase-side of the piston past the piston rings into the combustion chamber.

No bueno.

Engines are designed for positive pressure. Oil drawn in the combustion chamber causes depostis on pistons, valves and spark plugs.
If you odn't have to use engine braking, don't.

 

Engine braking happens every time you release your foot from the throttle. There's no practical way of not using engine braking. It's also not bad for the engine, they're designed for it.

 

this ^

maybe more oil consumption with heavy engine braking

but negligible