From what I can work out, different genera, require different ratios of the main and micro elements for optimal growth.
Not enough emphasis is placed on the importance of calcium which is often not in orchid fertilizers. You cannot buy a fertilizer with all the elements above as they do not mix and store well. Powder formulations will go gluggy in a matter of months with all of these ingredients!
Boron helps a plant absorb Calcium, and Calcium helps the plant use Nitrogen. Calcium is not translocatable and needs to be continually fed.
Excesses of micro elements can be toxic and fatal for plants.