Seating and crimping in the same step shouldn't cause a problem as long as you set for a light crimp or no crimp.
I have loaded thousands or rounds of jacketed 9mm (and other auto calibers) with just a sizing die and a competition seating die on my turret press. No flaring and no crimping at all.
With plated bullets I flare the cases very lightly and after seating that flare disappears, so I don't crimp there either.
This is for practice ammo only, but not flaring or crimping has not caused any problems for me.
Lead bullets get the Lyman 'M' expander and a separate taper crimp.
I have loaded thousands or rounds of jacketed 9mm (and other auto calibers) with just a sizing die and a competition seating die on my turret press. No flaring and no crimping at all.
With plated bullets I flare the cases very lightly and after seating that flare disappears, so I don't crimp there either.
This is for practice ammo only, but not flaring or crimping has not caused any problems for me.
Lead bullets get the Lyman 'M' expander and a separate taper crimp.