Paul,
I do not run an evap canister on my truck so I can't really give you any first hand experience. But there is a check valve in the canister, the TRD SC doesn't add any additional check valves. A lot of ways to skin a cat I suppose.
I have not added anything of that nature to mine. The only routing change I made was moving the PCV hose to the throttle body adapter along with the brake booster line.