ManNamedJed is probably talking about setting up your sizing die on a tool head by itself so that you can lube your brass, size it in the loader (with sizing die by its self in a tool head), remove it, run it through the tumbler to remove lube, trim it if needed, then run it through the loader again this time to prime-powder-seat-crimp (your second tool head).
If you try to do it all in the normal progressive way it can make a mess with the case lube all over everything. At least that’s the way I do it on my 550, on the 650 I only run pistol cases through it.