I'm trying to find the article, but am failing at it. But recently I read of a red 4th gen with a snorkel that got totalled from a water crossing. It was in a Toyota Land Cruiser magazine that comes every other month, the name of the magazine is eluding me right now.
The gist of the article was the vehicles computers were all lower than even the factory intake height, and after the vehicle flooded with water in the passenger compartment, it died and had to be towed out. The insurance company wound up totalling out the truck.
Just a heads up that while you might not swamp the engine, you certainly can swamp the electronics which is probably worse. I seriously doubt the snorkel will give you any more ability to cross deep water.
Plenty of other stories of FJ Cruisers frying electronics after water crossings on the net, so just a heads up.