Not at all, moondog!
Feeding until nearly asleep is fine. Next step is to teach him to accept the transfer into his cot.
I found that stroking the baby - in the cot - was a good way to help them learn. Just quiet, rhythmic stroking, in the dark room. No talking or singing. No body contact other than your hand.
The baby may cry, but it won't be from fear or distress. It will simply be because they're not getting what they wnat or are used to.
Don't try to sneak out on them. You can either stroke untilt hey fall asleep, and then leave, or until they are quiet and placid, and then leave. If the dc is distressed, return, resume and stroking. No need yto leave them crying alone.
It takes about as long as CC, often less. So you may find it works immediately, or you may find yourself going in and out for quite a long time - possibly hours - several times a night. But every night will need less. Eventually you will be able to stroke for a minute or less, then leave the room while the baby is awake.
BTW, listen to any crying before returning to the room: is the baby crying 'down' and accepting the situation and settling down by themselves? In which case, don't go back in. Or are they crying 'up' and getting more upset, in which case do go back to them.