I dont use any thickeners, a real bodge and cop out IMHO, I seperate the whites and whip them just short of merangue consistency, stiff peaks, then the cream must be whipped to the same consitency which is where all French creams fail, not a high enough fat content.
The egg yolks are mixed with the cream cheese, castor sugar and any other ingrédients plus gelatine, so I do use a thickener and the egg whites carefully folded in then the whipped double cream is folded in, if I were to use fromage blanc it would become a runny mess plus in my recipé at least you need the rich taste of the cream which fromage blanc does not have.
I am a fan of fromage blanc though, I make my own and get through 3 kg a week!!!!
Maybe I will try it in a cheesecake one day, trouble is its my best creation but I no longer eat any sugars so I only make it for others.