Before we got our 2nd 550, I would change the setup from 38 special to 45 colt fairly often. Out of curiosity, I timed the changeover process one time, from start to first pull for "production" loading, so it includes changing from large to small primers & setting the powder measure charge (we only had 1 then). 20 minutes.
5 or 6 years ago, we got offered a deal on a 2nd 550, so now we have 1 for large primers & 1 for small primers. It was worth it to not have to remove the primer tower every time.
Holler