I currently load for 2 cartridges that are "somewhat oversized" , one is supposed be .268 and is actually .270+ the other should about .312/3 and is almost .318 . I ended up with a custom bushing die for the 6.5×50 @ .270 . The .318 7.7×58 I found a 8×57 neck die suitable for 8×57J with a .318 bore .

Shooting cast and paper patch in both rifles as a means to reach a desired dia for accuracy . It quickly becomes obvious to me that sizing a neck per cycle upwards of .1 inch down , up , fired , is going to be hard on brass .
I've long been a neck/short size guy due to having started with a number of generous chambers that needed all the help they could get . I've made a few oversized expanders always with a long taper both ways and usually with barely enough room to size the neck .

The mandrill collet sizers seem like a really good idea , but after reading about adjusting the mandrill to get desired neck dia it seems that would effect the shoulder sizing and bump by stopping the neck sizing large . I don't any of those to test the theory .

The bushing die is a great solution . You don't have to expand the you just size it and it's done . But then for best results you need to neck turn to ensure consistent neck ID via neck thickness and annealing to avoid inconsistent spring back .

Adding the extra step is cheap but consistency of lube and speed of operations can become a thing too .

That's a lot of pessimism from a usually optimistic guy .

Carbide expander balls are probably about as good as it'll get for "hunter grade" precision . The virtue in them is that they are slick and unless you have a standard die on the small side and an over sized expander , let's say a 308 that takes the neck down to .304 ID then drags a .309/.310 ball back through it , is that there's minimal contact area and very low drag on that .
Without drudging off into metallurgy and why stuff sticks and drags that's the best I can do .

There is one more thing but it ventures in custom sizers , that is to lap the die neck dia of the sizer larger where you have one sizing in excess of needs . In reality a 308 neck really never needs to be less than .3055 , .3065 is probably enough but most dies will run them down to .304 , just in case the end user has thin brass ........