Yesterday I had a max bet situation where I split the maximum 4x and doubled all of them. If I was betting 2% of my BR for my max bets and had 2 hands, I would have had about 1/3 of my BR on the table hinged on that one hand. That's more volatility than I'd like to stomach personally, and would have been much greater than full kelly at the game I was playing. Playing more than full kelly is not advisable.