Well the best made plans of man or beast etc. I had this Prime tri-tip from Costco in sous vide for 6 hrs (planning for 8hrs), but had a sudden unexpected medical emergency, which required surgery. So I pulled the TT before leaving the house and froze it in the bag. Returned home the next day and took it out to defrost, and gave it to my Son-In-Law to complete. He pan seared it and brought it to Med--Med/Rare, with a good crust from the pan. Saved a piece for me which I ate Monday, and it was fantastic!. At $9/lb it was not a bargain, but well worth the purchase. I will try again to do it your way when I recover (10-14 days). Just used Montreal Steak seasoning.
No added garlic as there is plenty in the MSS.