In large amounts (did you see the amounts in the study?) They're bristley so most things won't eat them anyway.
Also this thread is a few years old....🤣
The only one that comes up for me is in Virginia.
They've only been around a few years so it's likely they're just breeding cackle stock anyway for a few more $$$.
I'd skip them.
Cackle is a much better bet for birds.
Rose comb brown leg horn.
With your climate you want small combs, leg horns have historically proven feed conversion rates.
"Friendliness" is up to the individual bird, it's not breed specific.