I wouldn't worry too much about any typical small kitchen appliance. After all, housekeeping stashes some commonly used small appliances such as electric teakettles, blenders and mixers. Any of those may be requested if available. We always bring our electric kettle and have never been told it wasn't permitted. Housekeeping had to have seen it on the kitchenette counter.
As we once loaded the car in front of VGF1, people in a van were unloading a bread machine, George Foreman grill, panini press and a couple other namebrand appliance-labeled boxes.
I initially thought they might just be boxes used to pack other items. Then, one person said to another about to lift the bread machine box onto the luggage cart, "Don't you dare drop the bread machine or grill."
The bell CM was near the van and had to have heard that. We didn't observe anything looking like they were being told they couldn't bring in the appliances.
Several years ago, I know people were warned not to bring electric skillets, slow cookers or toasters for regular hotel rooms. Those weren't allowed in rooms with no kitchen/kitchenette.
A non-electric single burner could be prohibited, though. No idea about one of those.