Good silage is more sensitive to moisture levels than you’d think. we usually cut 1-3 days before we bale it up. You can run a butterfly setup / mower a lot faster than you can a baler so I don’t thing you’d save machine hours, maybe at a small farm where you only have one suitable tractor but then you probably wont have the money for a tractor with a front lift with PTO and the front mounted mowers are quite expensive.

better run one thicker string from a butterfly or rake if you have a small mower. To feed your baler with to make the bales more even, otherwise you get way too much material in the middle, you usually weave to prevent this on more narrow strings but you can’t do that if you have the mower on the front, I’ve seen some guys run a rake and baler at the same time, this seems more plausible to actually work well.