Does anyone have any idea of what would happen if a cake frosted with cooked flour buttercream was frosted and frozen, then defrosted for serving? I also wonder if, realistically, it would taste as good? Does anyone have this kind of experience with cooked flour buttercreams? 

I know this isn't a popular frosting in the decorating world, but my family and friends love it. I have to make 2 12x18x2" cakes and a 2 tiered (10" round and 6" round) cake for a family party on the same day and I am planning on using this buttercream. Considering this, plus all of the other work that is going to be needed for this party, I am trying to do as much as I possibly can ahead of time. I would like to bake, frost, and decorate the cakes and freeze them, and then defrost them for the party.

However, if this frosting is refrigerated (before being applied to the cake) it needs to warm up a bit to be spreadable. Then, it separates, and it needs to be rewhipped for quite a while until it comes back together. Except, I haven't noticed any issues with the frosting doing this once it's been applied to the cake (the cake can be frosted, refrigerated, and allowed to come to room temperature and there is no separation). Freezing is obviously a little more extreme and I'm concerned about what would happen.