But seems to me that if she feels this way about people using her material, she'd probably feel roughly the same--at least in the abstract--about similar fanac in general. You don't think?

Nope-- I skimmed back through one of her books at the library yesterday, and the vanished long-ago homeworld of her Elves-from-Space is named after Tolkien's Numenor. Also, especially in Blackmantle, many of her characters are named after real people-- either as (usually) Celtic calques or as anagrams. Which, come to think of it, may've been what put me on her trail in the first place, from hearing that she'd given Katherine Kurtz a cameo role of that sort.