Carve pockets not working

Isn’t that only going to work if I actually had a 40mm wide V bit?
What can I do to cut a flat(ish) bottomed pocket that’s wider than the bit?
I’m after something like the flames at the end of that video, or this thread: Carve Machining Order Frustrations

It looks like I should be able to get it to switch to another tool and mill the middle of the pocket with a flat bottom, or mill it with small ridges with the V bit.