Only as far as smoothing your slope, so as to mow.
When in the perpenducular position, when cutting the swale bank, once that cut is done, ( but since that is done...) reach back, to where the boom is at a 45 degree angle to the ditchline. You'll need to raise yourself up some one one stabilizer, to make the bucket match the slope. You'll basically be raking the slope with the bucket teeth, bucket pointed straight down, cutting off the high spots, and filling divots. That is one advantage of a RT hoe, over a track excavator, unless you have a swivel boom, such as on a Gradall, bucket tilt head, or tilting upper structure as on an 880 Case hyd. excavator.
The raking action will give you a little "cream" to work with. You can clean up, what you brought up, when you move ahead. Just takes a little practice. You can always cast aside what you don't need, when it's not worth the time to move that pile of dirt, and clean up later.
I'd guess you could work a finish with a regular 3 pt. blade, turned backwards, at somewhat of an angle. Drag it with something, even if a weighted piece of chain link fence. Seed it, then roll.
I'm not sure how much reach you have, but on anything I've operated, whether it be a RT hoe, or excavator, centering the pivot point of the boom and stick on the cut your able to make, makes cutting a 3:1 slope a LOT easier. And even with an excavator with 20' of reach, I've had to make 2 passes, depending on the depth of the swale. Equal action on the boom and stick usually makes a pretty nice slope. But that action is only good, until it reaches the point where the boom is straight up and down. At that point, you'll need to boom down.
Lots of seat time is the answer...
