Well, I dont know what scientific proof there is that beefheart is 100% a bad idea.
But i can tell you that I've been making a beefheart recipe for all my fish for over a year and my fish are increadibly healthy, colorful and I couldnt be happier with it.
But I should say that only a portion of the recipe includes beefheart.
And I cut it up into tiny pieces, ***trim off ALL fat and veins.***
Then stick it in my mini food processor and mix it with raw shrimp, white fish, Omega one pellets, algae wafers, frozen peas, and I also mix in Vita-Chem and Garlic guard.
When it's all processed together into a discusting mush.

I separate into sandwhich bags and flatten them, then stick them in the freezer.
To feed, i just break chunks off.
My fish go totally nuts for the stuff. There's no fish that I have had that wont eat it.
I do also feed pellets half the week and the recipe the other half.