Thank you. I think I will need to use epoxie as you suggested because the quartz countertop is laid on top of 1/2 inch ply wood which leaves little thickness underneath to screw the brackets into.

Also I wonder if you suggest clear caulking the edges of the Ceran surface to block out food and guck?

I would buy shorter screws for the brackets and follow the instructions on page 7 of the Installation Manual to attach the brackets to the plywood.

I recommend against caulking in any manner that would be extremely difficult to remove sufficiently for the unit to be lifted out of the counter. Also, some induction cooktops (early Electrolux/Kenmore for example) expect to use the gap for cooling air. Otherwise, it might be OK if a bead were such that a razor blade could easily de-adhere it from the quartz.

The blobs I raised as a scheme were to be under the counter, and then very sparse.

The brackets dont screw INTO the wood, but up against it. They are there to clamp the unit down to the counter top. Tight enough to hold it still.

@weedmeister: This may vary with model. Mine have been of the type intended to hold the unit down, but also capture the chassis so it won't fall. Mine are cemented to the soapstone and screwed to the unit base.