Similar to other posters, my twins also were most comfortable sleeping in their car seats. We also swaddled very tightly and used white noise. So that's how they slept (very well, I might add!) till they were 4 months old (we DID put the car seats INTO their cribs so at least they were IN their room, in the beds they would eventually use to sleep). We then transitioned them to being swaddled IN the crib, and then got them out of the swaddling "habit" but by 4 to 5 months old, they seemed "ready" for this and transitioned fairly easily (still slept wonderfully from that point forward; not sure if we were just lucky or if "teaching" or "helping" them to sleep led to good sleepers - no idea).
My daughter also did end up having reflux so for her it was more comfortable to be elevated at an angle, although once she was on medication, it didn't seem to matter as much.
I say if you and your son are able to get more sleep this way, go for it. In these early weeks and months, I feel like it's survival mode and you can work to transition or "break habits" when they get a little older....Sleep is so critical for both you and your little one right now.