It’s commonplace that people gripe and worry about warped and domed cookware and unevenly cooked results. Why? Well, aside from the aggravation of $-$$$ wares deforming and perhaps rocking/spinning, the big culinary reason is that oil will pool in low spots, perhaps leaving the high spots bare and dry.
Most large appliances have come with some sort of leveling feet or nearly a century. Small appliances, like electric griddles and hotplates of all kinds, generally have not, even to this day. Yet the same need–and same unwanted effect–exists with these cookers; a flat pan on a flat tabletop cooker will be as uneven as the tabletop or the floor. Actually, the need can be even greater, especially with the use of small appliances outdoors atop improvised support.
I recently cooked at a few locations where even the major appliances hadn’t been levelled (or had gone out of level). And places where hotplates had just been plunked down willy-nilly. I found a couple of instances where coil electrics that had been levelled still were effectively uneven by virtue of individual coils not sitting perfectly parallel with the appliance or rocking under uneven pan pressure.
And what of cooktops? If the counter surfaces into which these are mounted aren’t level, the unevenness translates directly to the pan and the food in it. I’ve never seen any provision made for drop-ins to themselves be levelled. Presumably this is because of the edge gaps levelling would cause, and if the gaps weren’t filled, cracked glass.
So, how seriously do you take having your appliances sit perfectly level? Have you measured after your stove or cooktop was first installed, or did you just stop after the appliance itself didn’t rock? Was it even on your radar? How much of a deviation from sitting dead flat are you willing to tolerate?