You sound like a guy I work with (opposite days) on 3x3s. We can’t work more than 5 days in a row, so he took PTO for one of his days then worked OT for our three days, then repeat. He was able to get paid for EVERY DAY for two months doing this.
The company I worked for put a stop to using PTO to get overtime, especially double time. Also, you had to get to at least 46 hours in a week to get the double time on the 7th day, which had to be a Sunday. People would come in for an hour or 2 and claim that as a day worked.