Just a note that Mutations are seen as something to be feared. Especially the obvious one. You got away with TDC but just be careful when granting mutations on the wide scale.
40K is not friendly to Mutants.
That's true, but I wouldn't have thought things like Brain Eating, Enlightened Essence, and even Psyker powers were discernible to an observer?
Similarly, is Mega-Intelligence and other mental and social mega-attributes?
See above, mutants are not welcome in most places, we can't really bound on mass mutation to save us
If I'm right, we just don't pick visually obvious mutations.
Making a decent number of our population psykers with the brain eater mutation shouldn't be obvious, and reasonably safe as Lorgar can teach them Mind Shielding - possibly extra safe if Lorgar can inspire True Faith in those with potential for it and we specifically target them for the mutations.