Black Stainer. What does good edible mean?

  In many a field guide, the black staining polypore Meripilus sumstenii (formerly Meripilus giganteus) has been listed as not only an edible, but a good edible.  Granted taste is subjective, and its not the problem of taste I have with this polypore. Its got a robust dark flavor, with some bitterness and sourness. Unique and pleasing, yet the texture is where it recieves low grades and puts into question its edibility.
     No matter how fresh I pick and prepare, there is a toughness that gets in the way of enjoyability. Some persons say to only use the wee plump tips of the leaves, as I personally subscribe to for Laetiporus.  Unfortunately even doing this, you run into its fibrous and impenetrable structure.

  


 Ive tried cutting it across the grain as you would a tough cut of meat. Ive sauteed it, simmered it, and used both in succession. Stewed and pickled to no avail. Sous vide has been avoided. All tasted marvelous, but left me chewing just a little too long. My last failed revelation was to use a French technique of 'confit'. I submerged the mushroom in a vat of duck fat and slow cooked for several hours. What usually will break down hearty duck leg proteins, was no match for our invincible friend the black stainer. I was left with an unctous richly flavored fungus, that was a good workout for my molars.
    

Tub of Duck Fat that I keep stored in the freezer

Maybe since mushrooms inherently soft and forgiving by nature, Im judging this too harshly. If it were a hangar steak, I'd not balk one bit.