Although the meat of avocado is very soft, it holds up surprisingly well to the high heat of the oven and stays stable without melting. (blog.paleohacks.com)
Transfer to the warm oven while you make the remaining waffles — the dry heat of the oven helps them set a bit. (101cookbooks.com)
Secondly, a water bath provides a more even, slower heat source than the direct, intense heat of the oven. (withsaltandwit.com)