I've recently experimented with placing an old electric 'glass' hob above the heat riser of my 6" J tube rocket in my workshop.
It's worked well for a month or so with daily fires of up to 5 or 6 hours, but today I had a roaring fire going and the whole top exploded and shattered...! Fortunately I was wearing some reading glasses and a thick coat so I suffered no injuries.
I know several forum posters have used or are using cooker 'glass' tops with no issues. All I would say is be very careful when choosing this type of surface and try to ensure beforehand, it can take the fierce heat from a rocket in the long term.
Opportunity is missed by most people because it is dressed in overalls and looks like work - Edison. Tiny ad: