I was going to say that these things are great for the kitchen, where you can have a constant flame on them and you dont bleed all the heat like you would on a pellet unit. But after looking at videos of it, I see it fits right over the combustion chamber. Yes, I do believe this will stay hot enough even with the lid open, and that is how I want to use a griddle, i want to be able to access it 100% lid open. This thing might actually work as a griddle on a pellet unit.
And I dont want to disparage something like Okie posted, or something like the Little Griddles, I think they are great products, just better suited for a kitchen range then a pellet grill!