What counts is after re-size, not the after its been fired.
So, yes they are shorter after firing (at least in the ones I shoot), but once re-sized they are their shooting length and that what counts
If they are past the max allowed length then they should be trimmed back.
So, you check them after re-size step and then trim or not trim.
I don't get too carried away, if I trim and they are between the two lengths I don't keep triming. No matter where the trimmer is set, some trim down more than others so I just mike each one.
The one that avoids all that is the Gerrard and I wish I could afford one (my brother has one and we do large numbers of 223 and I just stash it). If I get enough 30-06 I can do the same thing.