21mm internal width + 35c tire: grip concerns?

How overstated are concerns of variable grip on a wider road slick on narrow (relatively speaking) internal rim widths when cornering?

I’m running a 35mm GP all season on a 21mm IW which balloons out to 36mm WAM. It fits my bike perfectly but I definitely cannot go wider. The same rim with a 32mm all season is actually closer to 30mm on these rims so I wanted to see if I could go wider.

I want the bigger tire for more grip and more comfort with less pressure.

But I heard grip characteristics are changed when the tire balloons out when cornering.

This is a concern to me because I do a lot of hard descending and cornering. It rides fine on a quick test ride but it’s hardly the use case I normally take my rides on. Is this something I really have to worry about?