I doubt that very much and require proof.
I wish I could find simple ways to explain that. As already pointed out, the main reason canards proponent say that it is more efficient is that conventional tails must provide negative lift. It is a fact that the statement is not true. And even if it was, we are dealing with small amounts of force. At normal cruise speeds, induced drag is small compared to parasite drag so the additional induced drag on the main wing created by the need to compensate a small negative load on the tail is actually falling into the noise levels (again, at normal cruise speeds). On the other hand the canard has to deal with a wider spectrum of pitching moments (see why below) and must therefore be larger than a tail in the back. More wetted area, more parasite drag, less efficient.
So what else is left for Canards to be more efficient? Nothing that I can see.
On the other hand the list of severe deficiencies is long. I will name just one:
With landing flaps, the wing camber increases dramatically and a substantial pitching moment appears. What is neat with the tail in the back is that with flaps down, the downwash greatly increases as well. That increases the down force on the tail and neatly balances that pitching moment due to the flaps. On well designed airplanes, very small amount of trim is needed when lowering the flaps.
What do you do with the canard then? It does not compensate the new pitching moment since it's so far ahead of the wing. The upwash is comparatively negligible.
The Starship has variable sweep canard for that reason. Variable sweep planforms are not for the faint hearted. Heavy and expensive.
Yes that's what I worked out several posts ago.
I did not read it that way. For dynamic stability, it is the lift curve slope difference that is the key, not the angle of attack delta.