Not bad for a second bird. Left wing looks like it's not tucked quite right and the neck pose looks a bit severe. Keep up the good work, you're on the right path. Remember to always wear eye protection when injecting masters blend. It has an uncanny affinity for human eyeballs.
If you remove the legs from the skin, you can pose them on the mannikin, put a baggie over them and inject the feet through the baggie. Then you can paint them before re attaching to the skin, no over spray worries.
The legs are permanently attached to the mannikin and let dry. Then, mount the skin to it.
Hopefully we aren't leading you astray but you can do the feet at least 3 different ways (there may be more ??).One is the way you are writing about, cutting down the leg skin, and then posing/painting the leg with it staying attached to the mannikin. (You are removing the foot/leg bone(s) from the skin).Another way is to remove the foot/leg bone(s) from the skin without slitting down the leg skin. Then posing/painting the leg prior to mounting the bird. Then removing the foot/leg from the manikin and installing it thru the tubed out leg skin at the time of mounting up the bird.The third way is to leave the foot/leg bone(s) attached to the skin. Then at the time of mounting the bird, you can pose and inject the foot. After drying (meaning foot) you can paint the foot in place while your mount is "complete".IMO I don't like the slitting of the leg skin as I do a poor job of sewing that back up in an orderly fashion. I do method #2.Hopefully you will gather that there are usually many ways to do a certain task in taxidermy. My recommendation to you is to try a few of them and see what works for YOU and then go for that as your way to do something. Good luck on your ducks. You did really well for your second bird. On each successive birds try to do at least (1) thing better than your last bird and you will be well on your way.