If I remember right, the early KISS required a weighted bullet stack above the dropped bullet to "stick" those bullets well. Later post KISS M.B.F.'s include a similar "M" expander in the powder die to replace Dillon's
All of the “droppers” rely on a tamp of the bullet, even if you can’t buy boattail bullets in that caliber. Like this Hornady 9mm feeder.
The powder funnels for bottle neck cases, on Dillon and other equipment do not incorporate expanders and my KISS as well as MBF feeders are the same in that respect.
Expanders for bottleneck cases are on the decapping pin on Dillon’s and there is also one on the backup rod for the swage station on the 1050.
Pistol 1050, backup rod expander/flare only powder die (left), all other Dillon pistol powder funnels with expander and flare portion (center left), all Dillon bottle neck powder dies (center right),
if you tried to incorporate any expander in a powder die for .223 you would be in powder bridging heaven as it’s already a problem with some extruded powders even without trying to expand and flow powder through an even tinier hole than the bullet diameter, and on the right the 1050 back up rod/expander.
That said, expanders can differ quite a bit, even from the same manufacturer. The 3 on the right are all .30 cal Lee ones, technically #2 is just a mandrel but serves the purpose of a minimum.