Properly executed in two steps the case is sized on the up stroke and the neck expanded in same fashion. Do not use a full stroke with the expander. Just enough to pass through then withdraw. Doing so minimizes case distortion the asymmetric forces associated with the shell holder geometry cause.
I'm sure that works fine. But I've found that lubing the inside of the neck of a case greatly reduces the drag as it's pulled back over the expander. I usually scratch the case against the lube pad every 5 or 6 cases to scoop a little dab of case lube into the neck. One application of lube to the inside of the case neck will deposit enough lube on the expander to keep it slick for 5 or 6 cases and prevents the case from stretching as much as it's pulled over the expander.
All well and good B but removing the expander ball on resizing the case eliminates the possibility of canting the neck (the bullets steering wheel) as on the way out (as normal operation one pass sizing ), very possible to do as the press is at the top of its stroke and press tolerance could cause a canted neck. By just expanding in a separate operation the expander ball sizes on the down stroke and only needs to just pass through the neck . A dial indicated run out gauge lets you know if your equipment needs this or not. This and consistent neck thickness can make a significant difference .
If you are scratching the mouth of a few cases across the pad to get lube on the expander ball is the lube getting on the ball? the ball will not touch the case on entry but will on exit in normal one step sizing and may not get on the top (leading edge ) of the ball at all.
