I like using the progressive function of my 550. Since I also reload pistol cartridges on my press, I have built in muscle memory for the process. When I initially started reloading rifles, I tried keeping the seating die in place with the powder, bullet seating, and crimp die. The problem occurred after I full length sized the brass. Since the brass needed to be trimmed, I had to trim the cases and run them through the reloading process which meant through the sizing die to prime the case. After a few I also noticed the lube was inside the case neck and really not working well.
After some phone consulting with some friends and a person at Dillon, it was suggested that I place the sizing die in a separate tool head, size, de-cap, clean the flash hole, trim and re-tumble to get the lube off the cases.
The same person suggested that I place a universal de-capping die in station #1 on the tool head of my 550 and use it clear the flash hole of any media and to utilize the same reloading flow as I am used to e.g. size & de-cap, prime, drop powder, seat bullet, crimp, begin again.
This process only works on progressive presses with 4 stations and interchangeable tool heads like the Dillon. If you are thinking of using a single stage or a progressive without interchangeable tool heads, you will need to tailor your reloading process.
I hope this helps...