Any luck with crib and Merlin magic sleep suit? 4 month sleep regression help!

My son is four months old and we have been trying the crib for 3 nights with the magic sleepsuit. Before he was swaddled and in pack in play by our bed and was sometimes ending up sleeping in my arms.

I think he’s going through the 4 month sleep regression, used to sleep 3-4 hour stretches at the beginning of the night and now it’s an hour or 2 all night long. It’s been that way for 2.5 weeks so I decided to start the crib and swaddle transition since we weren’t getting any sleep anyway. He’s eating each time he wakes up. He’s a big baby, over 99th percentile height in 12 month clothes, 99th weight. 20 pounds. We tried rice cereal last night, he was not interested, exclusively breast fed.

Any advice on how long it takes for success with the Merlin? Should I keep at this?