EmmaB I think there's been some misunderstanding from colleagues above, apologies. The above mentions are referring to if you were simply to insert Gourmet Ads directly on your site, so that you have some Gourmet Ad locations and some Ezoic ad locations. This would lead to a decrease in revenue in almost all cases.
However, if we set this up via Mediation (which we have them listed as a validated partner, so it definitely should work!) - Gourmet Ads will only show in an ad location if the advertiser is willing to pay more than an Ezoic advertiser, and vice versa; so there's no risk of losing out on revenue and you don't need to worry about wrapping your ads.