The concept is great. Being able to make crispy potatoes, I found a very good idea. I tried this for a while and here I share.
I use shredder seasoned potatoes (approximately 1 inch size)
Use 36 mashed potatoes for a complete waffle maker.
Please note: potatoes thawed before putting them in the waffle maker.
For mashed potatoes 36 with 2 minutes in the microwave will be fine, they have to be soft but not broken.
With a bag of 32 ounces (2 pounds) you can make 3 good crispy waffles, of 1/2 inch high. Enough for 2 people accompanied with eggs, bacon or whatever you like.
I have also brushed with a little oil waffle iron to prevent sticking. You can also use Spray Oil.