Shallow frying might be a problem with sticking. Depending on what the material the bottom-inside is made of.
I would advise talking to someone who makes this type of cooker or to someone who has already deep-fried using one. There might be safety concerns that aren't obvious.
From Nesco's site:
"The Automatic Temperature Control provides a wide range of temperature settings from (200ºF-450ºF) which allow you to slow cook, roast, bake, steam – as well as sear and brown foods."
No mention of deep-frying.
From another site about seasoning a Nesco Roaster:
"Tips & Warnings
Your NESCO roaster oven should never be used for deep frying."