In your discussion of fishing with a dropper off of a dry fly you state that you prefer to tie the dropper at the eye to get the proper float.It seems to me that a dropper tied at the eye with a nymph on it will cause the dry fly to nose down ( I have tried it). Droppers tied to the bend of the hook may cause the back end to dip a bit but that is much more natural looking than the nose down approach. As a matter of fact the back end under water looks exactly like an emerger.