Question

Hello Rabbi,
I wanted to ask how careful one needs to be about cleaning the stovetop for Passover.
Yesterday our non-Jewish cleaner cleaned the stovetop using a grease remover. We are not among those who are extra stringent and search for every crumb, but when it comes to the refrigerator or the oven, we are more careful, since they have direct or indirect contact with food.
When I cleaned the stovetop myself in previous years, I thoroughly soaped all parts of the grate—both the upper side and the underside—and made sure the soap touched every point (maybe that was a bit excessive).
Since non-Jewish cleaners do not understand the parameters of our stringency on Passover, after they clean the couch I usually move it myself, lift the cushions, and check whether there is an olive-sized amount of leaven there. Sometimes I even find remnants of leaven.
And my main question is this:
Regarding the stovetop—do I now need to open every pot support and clean it again, or is it enough just to check visually that the grate is clean and assume there are no crumbs inside it, and even if there are, in any case there is no reasonable chance they would come into contact with a pot? Or, because this involves cooking, do I have to be stringent and open the support?
Of course, I am planning to do a light libun to the upper part of the grate.
Is there also a need for libun on the underside of the grate, which does not come into direct contact with the pot?
We are also planning to leave the fire on in the burners for half an hour.
I should note that we do not have the practice of covering the stovetop with aluminum foil.