Interesting. I’m confused too by your directions/question, and/but eager to know the answer.
I think you are asking…
Do you K1,P1 into first loop, then K1P1 into second loop of YO before dropping both loops off the left needle?
Or do you K1P1 into 1st loop and drop it off needle, then K1P1 into second loop and drop it off needle?
Or do you K1P1K1P1 into 1st loop of YO and then drop both loops off the needle?
And does it make a difference? i.e. Would the YO loops just straighten out, pulling through all the new stitches, creating one elongated stitch anyway?