Swingman wrote:

While I tend to agree on the surface, that's actually been proven to not
make much difference, if any, and certainly a "real" _angled_ tenon could be
much less strong depending upon the grain of the particular piece.

"Not much" difference is not "no difference". I know I tend to lean
back in chairs...so I'm partial to ones that are as strong as possible.

Certainly, and angled "real" tenon could be a problem.

As for the angled loose tenon...how deep were you planning on making the
mortices? There's no scale on the drawings.

Finally, what about leaving the rail at full dimensions? Are the legs
thick enough? Your resistance to racking increases with the third power
of the vertical height of the rail, so a small increase can pay off.

Chris