Binding off with dropped stitches

I am working on a Berroco pattern called Julianna. It has dropped stitches.
The issue I have is that the dropped stitches look like holes along the top of the sleeve. The sleeve are knit by picking up stitches. The sleeves are ribbed and do not continue the drop stitch. I am not sure I am binding off correctly where I drop the stitch.

There is a note in the pattern which says “When binding off sts, each time you come to a marked st, drop that st off the needle, allowing it to unravel back down to the beg. Cast on 3 sts and bind these sts off.”

I understand dropping the stitch. I do not understand the cast on/bind off instructions. Do I cast on 3 sts and then bind them all off? Or do I cast on 1 st, bind it off, cast on a 2nd st, bind it off and cast on the 3rd st and bind it off?
What cast on method should I use?
It seemed to work better when I did 1 st at a time. It didn’t make sense to me to cast on 3 and then bind them off.

I cannot find another pattern where it instructs you to do this when you drop a stitch.

Any help would be appreciated. I had the body completed and 1 sleeve 90% done. I took it apart and I have started over. I have tried a few swatches, but I still have a hole. The picture on the pattern does not look like the dropped stitches by the top of the sleeve pull open.

This is a dropstitch pattern. At the very end, you drop one (or more) stitches and unravel them to give the knitted item a special look.
I never used that technique, but as I understand it, you drop one stitch, to let that unravel to the end, then you cast on 3 stitches and bind them off to make a “bridge” of some sort.

So, after dropping the stitch, you cast on 3 stitches (look up reverse loop cast on if you want, I think it’s the easiest for this situation. You can also try knitted cast on).
Then, you bind them off, and, as I understand it, end binding off with the stitch that was next after the dropped stitch, before the cast on, so that you connect the stitches on both sides of the dropped stitch.

Is that any clear?

Another way you can do this instead of casting on/binding off, is pick up 3 sts in the yarn strand at the top of the drop st. So drop the st, knit into the strand, bind it off, knit into the strand again, bind off that stitch, then knit a 3rd time and bind it off. Seems like it would be easier.