You can set one up to run full loads or sub loads. I haven’t tried but heard it’s difficult or impossible to cycle both. I’m not advising to do this but I’ve read that you can not over pressure a 223 using trail boss. You can mark the case where the bottom of the bullet is seated and start there working down to 70% of that load. In that range you should find 1050fps.
Cycling a reduced load in the 1300-1500 range would be easier than a sub load.