the medium is just a vessel for water. what else are you doing differently? different strains? pretty hard to compare past and present results when it is a completely different plant.
the plants i've grown encompass the whole spectrum of bland to flavorful. That leads me to believe it is mostly genetics. The composition of buds does not change due to diet. the cell walls are still made up of the same molecules and elements... the nucler envelope, chhlorophyl, other organelles etc all have a specific instruction set that cannot deviate or they won't function properly and the cell won't function properly. Since a flower or pollen sac is a sex organ, it did not evolve to fulfill the role of storage. common sense contexts of a fairly healthy plant, just in case to narrow scope.
it's a deterministic world out there. cause and effect. it doesn't matter how the co2 was formed, it will always act like co2 is expected for a given a context. The building blocks used are the same by the time they are jig-sawed together for whatever cellular growth it is invovled in, flower will be flower / stem will be stem - with a bit more range than a simple molecule like co2 due to greater complexity of what's going on... relativistic factors and such muddy the waters quite well at times. any ratio achieved of what is provided can be matched atom for atom with soluble, chelated nutes.. not saying it is happening with any product or even the ones i use, but definitely not impossible with existing knoweldge and tech. nothing mystical about the composition of some earth.