Did u carry him during the newborn time (confinement time) very often?
If you are ok with introduce yao lan, why not. My no1 uses it until 6 months than i wean off as she doesnt like yao lan. While my friend still using it till now for afternoon nap, going 3 years old soon. He used to relay on yao lan too, but took a bit of time to let him get uses to sleep on bed, but tt is when baby is a bit bigger. And they are perfectly fine.
At least with yao lan, you can bath, eat, etc. after using yaolan, than u have to start to slowly wean him off relaying it, like at night once deep asleep, move him to bed.
Do u have rocker? Even after he is deep asleep move him to rocker and slowly rock him and let him continue sleep and slowly stop rocking.
Have to trial and error to find the suitable ways to let ur LO sleep.