I have made chairs and repaired many also, the purists always use mortise
and tenons, for the most part I use dowels.
Regarding the front leg joints using mortise and tenons results in so much
material being removed that this is a primary failure area . Using a
combination , dowels and M&T seems to me to offer advantages, less material
removed and the double dowel if done last locks the tenon in ...
Any thoughts on the matter ???? mjh