zen monk revisited

i was torturing myself at job recently and found...
necklace of eye partially helps for blind chars.
In particular it maps surrounding squares and items on one. Monsters
are unseen as localization of character (which can be easily checked
with attempting to shoot anyway).
Only blessed necklace has this ability to act as "third(?) eye". Even
extreme Perception values (>90) doesn't make mapping radius larger but
still it is great improvement. Sensing seven squares instead of one,
having map instead black screen... (still no scrolls, books and no
idea on that exact item you are standing on)

Of course the question is if char with early necklace (possibly from
black market) wins the game how it does proves it was really Zen Monks
challenge. Save file won't prove much as most levels will have maps on
them...

And i do not think this is against challenge rules. Overall Zen Monk
comes from Net Hack blind samurai games. and iirc things like certain
amulets allowing seeing living creatures while blind there nowhere
close to forbidden.