I've used a tiny amount of meyer lemon juice in a blonde ale last year and it definitely did not go over too well. The acidity of the lemon just completely overpowered the whole batch, it made your face pucker, coming off as medicinal, and even after aging for a year it still has that acidic un-drinkable quality...the amount used was around 1 teaspoon per gallon.
I know that in baking lemon juice is used to "bring out" particular flavors, however you are also dealing with solutions that tend to be more alkali (such as batters and doughs)...and those products also tend to have stronger flavors involved anyway. Also, in baking the residual sugar content tends to be incredibly high (of course!) which also happens to be a major flavor component of any type of fruit...without the sweetness it just tastes like nothing really...think of really un-ripe anything, or really unripe watermelon it has absolutely no flavor.
I've found that some of the "fruity/woody" hops at flameout tend to accentuate any type of fruit ale...i.e. Fuggles or Brewer's Gold as well as aiming for a higher F.G.
Also, you can always add more blueberries to your secondary (keeping in mind that it will continue to ferment with each addition).
Good luck with your fruit!