It all depends on preference. Lady Shadetree and I have never cooked inside with any camper we've ever owned. We prefer to keep the smells outside the camper. So when I built ours I added a sink but no cooktop. I keep thinking a single burner would be nice to make coffee on in cold weather, but even having a butane stove for this purpose, we've never used it inside. Go with whatever you think makes sense for your purposes.
2012 Ford E350 EB 5.4