Still happens. I know of instances where competitors fished the lake the entire week before the tournament and put their biggest fish in a fish pen at some remote place on the lake. On tournament day they went back to retrieve those fish. They were small local tournaments though. But you’re right, it is harder when you have to bring in live fish.
Yeah I’ve heard of people precatching fish and using holding containers.
That one’s been around for a long time.
Harder to do in saltwater tournaments.....the ones I’ve been in really are under the honor system.