It will never take 2.5 hours and I'm pretty sure there is no direct. The best is to get to Rayong city bus station Terminal 1 (not terminal 2) and then get one of those small 2 benches open cheap buses (xong-tail) which takes you to ban-phe pier in max 30 minutes.
So I went to immigration yesterday with all paperwork.
I started by giving her my passport and TM47. After 2 minutes she gave me the passport back along with the new 90 days notification date receipt.
She said, that's done, you're good to go. She didn't even look at the fact the TM47 I gave to her hadn't been signed yet, and it didn't have a date on it, so I told her so and I did sign it and left, thanks