How do you handle a customer who orders "extra everything" every single time?

We have one regular who asks for extra rice, extra beans, extra protein, extra cheese, double guac, and gets annoyed when we charge for it. He's polite, he tips, he comes in three times a week. He also costs us roughly double on food and the burrito is genuinely too big to roll properly, so it falls apart and then he tells us it fell apart.

I don't want to lose him but I also don't want to keep eating the margin. How are others pricing or capping this without making it a confrontation at the counter?