I got so excited when I saw this, I'm working on a bunch of blueberry recipes and this is one of them. I am also trying to replace yellow cake in my cupcake recipe but I'm waiting on a new shipment of bottles to come in before I can start the actual mixing. We're clearly going to have very different end results as I don't avoid diketones but there is a way I see I can help.

I'm imaging CAP Whipped Cream is supposed to be the topping here, if you're dead set on Whipped topping try adding 1% Marshmallow (not CAP Marshmallow it's just too heavy for this application) TFA or FA would what you'd want here. In my recipe I'm actually using a 1:1 of FA Meringue and TFA Marshmallow, it provides that sugary topping while actually filling blank (flat) spots in a blueberry cake recipe.

As for FLV Blueberry Muffin, I have this flavor, it's a good flavor but to me a blueberry cupcake screams artificial blue flavor. This flavor can be found in TFA Blueberry (wild) mixed with cake at 5-6% as for TFA Acai I've found it comes out quite grapey. Alternately if you're looking for a REAL blueberry flavor try adding in FA Bilberry to your original recipe starting at .5%.

For the cake problem I'd try adding in CAP Sugar Cookie at a 1:1 with TFA DX Vanilla Cupcake OR CAP Vanilla Cupcake v2, not both. I've had really good success at 4-5% total bakery flavoring but if you're keeping FLV Blueberry Muffin in the mix that tip probably isn't going to apply here.

I hope this helps you out. If anything I suggested has diketones my bad, I just didn't know because it's not something I'm concerned about in my own mixes. Sorry I just didn't share my recipe and explain my reasoning behind it but I don't really want to share anything until I try to eliminate the FW Yellow cake from it. Just doesn't seem responsible to do so.