I had a P card and would expense food on the road, so no per diem to worry about. I didn't travel super often, so I would use this opportunity to treat myself on the company dime, choosing food and drink that often went beyond the limits of what we were allowed to get. So I would just pick whatever the fuck I wanted and tell my server/bartender that I was gonna be splitting my solo check: $X on company card, everything else including tip on my personal card. I'd get whiskey or beer or wine and steak or lamb or something like that. I would wind up with excellent meals for like $10 out of pocket. But because I rarely traveled, my company mileage and fuel costs were like 5% of everybody else's in my district, so my monthly expense reports were almost always under $1k (usually more like $300) while everybody else was routinely $5-10k. So thankfully, nobody was dumb enough to give me a slam dunk malicious compliance story haha.