It can be done with thigh straps and technique. A calm pool helps too. Here are a few vids I dug up years ago. Some look pretty ancient; perhaps the mastery of IK rolling has become a lost art.
Of course the fact is most IKs are usually so wide that falling out takes some effort (left). Getting back in to an IK is usually as easy as crawling drunk onto a sofa. But that’s not so entertaining to watch.

First up. The IK in the old video below from theboatpeople is a self bailing Aire Lynx (right); 32lbs (14.5kg), and no less than 37 inches wide (94cm).

Here’s another. Don’t know what it is but it looks even wider – perhaps a small raft? The guy gives it a go but eventually separates from the boat. Nul point. As the lone youtube comment says: “Nice briefs, bro”.

One more? A Gumotex Safari with a long lever roll. At 28 inches wide it’s narrow for an IK and probably the easiest one to roll (not that I’ve ever done it, mind).

And another. Tahiti is a Sevylor IK, I do believe. Nice execution.

Another Aire – looks like a 36-inch Force river runner. He gets there in the end.

More pixels here than Disney, but no long levering required in a vintage Spreu Boote Guppy. What is it with these European IK names?

And finally the Packmaster, Roman Dial and chums demonstrating packraft rolling with and without skirts. There are plenty more packrolls like this on youtube.