Burdock leaf, root safe for rabbits?

We have pet rabbits, and plenty of burdock.
The Internet runs hot and cold on feeding rabbits burdock leaves, but roots are seeming just fine, a special treat even.

These bunnies get jchoke greens, mulberry, grape vine,comfrey, pear tree and lambs quarter, pretty regularly, so they can deal with "wild food".
I'm very careful about tossing them just any old weed- my wife LOVES them deeply.

Does anyone here feed their rabbits burdock?