Howdy
I only load cast bullets and they all have crimp grooves. I simply set up my dies so that the crimp is formed in the crimp groove. Period. I don't worry about Overall Length. Most of the time cast bullets are designed so that if crimped in the crimp groove, the cartridge length will take care of itself.
There is nothing that says that cartridges need to be loaded to Max OAL. Usually anything up to Max length is fine. I have an Uberti replica of the Winchester Model 1873 chambered for 44-40, and it functions best with ammo loaded about .010-.020 over the recommended Max OAL for that cartridge. Anything shorter and it does not feed well.
It is true, that one can vary Over All Length slightly by shifting the bullet a few thousandths one way or the other, but too much of that and you are no longer crimping in the crimp groove. A revolver simply does not care how long a cartridge is, as long as it does not stick out of the front of the cylinder. Rifles are a different thing, OAL can have an effect on how the rifle functions. But again, all my cast bullet loads get crimped with the crimp in the crimp groove and I have no problems. The OAL is whatever it is.
And I always seat and crimp in one step. It is not all that hard to do. Separate crimp dies are highly over rated.
P.S. It is a good idea to always make up some dummy rounds when first setting up your dies. Sacrifice a few bullets and pieces of brass making up some dummies while you are still fine tuning the adjustment on your dies. Don't start cranking out live ammo until your dies are all set and locked down. Save the dummy rounds for future reference. If you ever need to change the die settings for a different bullet, you will have the dummy rounds to help you get back to the original setting. Lower the seating stem until it contacts the top of the bullet in a dummy round, and you have re-established your OAL setting.