It is tight and easily mucked up. Springfield convinced me to try it. It is not an easy project by any means. Fortunately, but expensively, I ordered new cylinders to try it on; as I wanted to be able to swap back and forth.
First, not every reamer is the same and getting a reamer with an accurate profile is, well, let's just say the spent brass definitely needs full length sizing. Getting the new bore right actually requires a slightly offset/angled ream so the rims don't interfere with the ratchet. Wound up making a jig to fit on my drill press, manually turning the reamer, so I could accurately ream it out.
In the end, I don't bother using them. Just shoot .44 Russian (in BP when possible) in the original cylinders. Oh, yes, there is enough material reamed out that I only comfortable shooting BP when using the .44-40 cylinders.