They will work without insulation, just not as well. I'd not use one over a canister stove due to potential overheating the butane canister but I have used them over a Nova and a 413G Coleman twin burner. The 413 and oven are a perfect match so...Gray...put one on your 'next to buy' list
You pretty much need to over heat the butane canister to get any sort of heat out of those stoves anyway! I am not a fan of them. I have an outback oven I have used on my Coleman 424 and dragonfly with great results.
As rik says get a Coleman suitcase stove ( oven fits better on larger 413 or the 3 ring one) and you will be blown away. I find them better and more powerful than my stove in the kitchen.