Find the 2nd clue here.
Thank you for your comments, they helped. Let's see what you think now...
Edited to add:
No, it doesn't hurt to shorten the leg, but it should be shortened by a whole repeat, otherwise the pattern doesn't work out.
Apparently I have put 17 rows into the S/L repeat chart for the sock, though the repeat is only 16 rows high. Sorry about that.