The small blocks are because the brass is too short to reach the trimmer in the die. Currently I only have one for the .300BLK and I suppose you could maybe install the trim die in there but I've never tried it. I'm not sure why you'd want to do it though.
You're better off getting two toolheads per caliber. I get the short one for the ones that recommend it, but calling Dillon is also a good idea because there may be some rounds where it's not required but would be handy (and may work for the calibers you mention). I use the cheap cast aluminum ones and just write with a sharpie what caliber it is on the front and the loading head sits on the stand. The prep block sits on it's side in front of it. I tend to have complete setups for changeovers, I don't mess with dies once they're set, and that's the best way to go even if it takes some time to get all of it. The extra parts also come in handy.
Anyway, use one toolhead for prep, another for loading. For prep, install the trim dies in the toolheads and swap the trimmer around as needed. Leave the die set. Also, those trim dies? They're also full length sizing dies, many of them, just be sure first. If you use those and an expander die after it, which can be had cheap from Sinclair, you don't even need a sizing die, but beware if you do use a sizing die to not undersize it with the trim die later. And if you use the sizing die, just adjust the trim die just so it's not touching the shoulder so it'll trim only.
