Sloping gardens

I changed my gas hob for induction very recently and although I have replaced one iron pan because of the weight, I still use my cast iron griddle hot enough to make naan bread. The glass has discoloured slightly, but my main gripe is that the touch controls don't work unless scrupulously clean and dry. 
But in general I'm glad we made the change ... although I have kept a two ring wok burner hob as well 

Umm, so today I found that my cast iron ridged griill pan had a small, hard nodule on the base and consequently the hob is  scratched. MrPP has ground out the flaw to prevent it happening again. 
Reading up, it would appear that you can actually put a bit of paper - cooking parchment, even kitchen roll - between the hob and the pan which I'll try tonight. If you hear of a big house fire down my way ...