They should only need to be there but a few weeks. Just cut around them until they can be removed. That's what I did. I wouldn't even trim anything close to them, just leave it longer near the flags. It's only going to be a few weeks and then they can be removed.
I'm confused. You said you left and found another lawn to mow. You didn't bother to do a scheduled lawn? Wouldn't that throw your schedule off?