Extracting oils and flavours before fermentation Distillation of ethereal oils is made with different pressures and temperatures than distillation of alcohol. So when distilling spirits out of mash directly most of the tastes get lost. I wonder if it could be an idea to distil the natural oils and flavours of fruits (ingredients) before fermentation and add those components later to the product to conserve a stronger taste of the ingredients used.

Has somebody tried that out?
Actually, yes. Though usually not with essential oils. In most cases, as an infusion. 

For low-alcohol beverages: punch, some dry-hopped beers, vermouth 

For spirits: liqueur, gin, rumtopf, Chinese paojiu

Compound gin is an example where essential oils might be used.