The thorns are separate from the flowers they grow on, but I did add in another line if you passed that check for 1.10 <3
As for the skipping that's a ren'py function and completely beyond my purview and capabilities. One thing that happens is that if a line has been edited at all it counts as unseen, so maybe you are running into a few lines that have changed since you first saw them?
Sorry for any inconvenience!
<3