If baby isn't rolling I would keep the swaddle.
Establish inconstant use of a dummy, if you haven't already. Makes a huge difference.
Are you winding effectively after every feed? If you are feeding frequently you also need to be winding a lot otherwise trapped wind disturbs sleep.
What are you doing to get baby to sleep?
During the day I'd suggest dummy and bouncy chair. Even tempo boucing with your foot all the way through sleep. 20 min naps aren;t the issue - too long awake between naps is the problem.
Wake Window wants to be around double nap length. So 20 minute nap means that after 40 minutes awake baby should be back in the bouncer with dummy for a bounce to sleep.
At night, dummy, swaddle and sidecar cor is possibly the easiest way to achieve independant sleep. If baby wakes, open swaddle, feed baby until refused, put back into swaddle and onto your shoulder, wind upright until at least 1 burp, back into cradle hold to reoffer milk until asleep or refusing. Dummy in, lift back to shoulder for final wind, then slowly slowly lie yourself down in bed and at the same time lower baby into the sidecar cot, while keeping body contact at all times. Cuddle into the cot, tap dummy to encourage sucking. Extract yourself once asleep.