Sealing hob to worktop

I just fitted a ceramic hob into a new worktop, and the only sealing supplied was a very narrow adhesive foam strip. It is far smaller than the recess on the underside of the edge of the hob.
I would use silicone sealant, but the instructions for the hob warn you against this.

I don't want spills leaking down through the join, so should I just ignore the warning and use sealant?