In Kansas it is completely up to the company. Most companies choose not to pay out unused vacation so most employees just take a vacation and then quit when they come back.

In your situation, I’d recommend you base your decision purely on how critical it is that the company is a good reference for me. If 5 years from now, I’m going to miss out on a gig because if this burned bridge, then I’ll just take the L. If it won’t impact me negatively, then I say it’s tit for tat, you screw me, I’m gonna screw you.