Please find our technical protocol GL as attached, I think Ms Lien showed to Mr Peter already.
You can find our standard is no need to use sleeve for 0.31mm and up (applied for FH-G550)
If no any special request from customer, we just do as our Mill standard. In this case you request 0.33 should have Sleeve inside, we will do for next order.
But we consult you that thickness from 0.35 and up no need to use Sleeve to save cost, but if you request you will see in my offer in future price will plus some usd