I dont think that you would have to recess i deeper, just some good rtv but make sure that that you rough up and clean the surface you will be putting the rtv on so it makes a better bond. To rough up the response area just use some low grit emery paper the clean of all the dust that comes up with some mineral spirits then simple apply the rtv and let it set.
It depends on the year/edition/production run. The older G5’s used pad recesses that would not hold silicone very well. The new ones will hold it just fine. What response system did yours come with stock?