If the public key is revealed it is still safe from bruteforce if the attacker don't know the range of bits to search for?
Of course.
Many blocks mined by Satoshi have txs with "pay to public key" script (P2PK) instead of "pay to public key hash" script (P2PKH, pay to address).
The public keys are known, but the btc are still there:
block #100
https://www.blockchain.com/it/btc/tx/2d05f0c9c3e1c226e63b5fac240137687544cf631cd616fd34fd188fc9020866PUSHDATA(65)[04
e70a02f5af48a1989bf630d92523c9d14c45c75f7d1b998e962bff6ff9995fc5bdb44f1793b3749 5d80324acba7c8f537caaf8432b8d47987313060cc82d8a93] CHECKSIG
x = e70a02f5af48a1989bf630d92523c9d14c45c75f7d1b998e962bff6ff9995fc5
y = bdb44f1793b37495d80324acba7c8f537caaf8432b8d47987313060cc82d8a93
you say we could calculate a specific search space when we know the pub key from these addresses.
but why are the BTC still there ?
is it also impossible with the specific search space ?
i have a list with 42k of this addresses
I believe his explanations were clear. He could calculate the private key from a minimal range e.g 2^80 but cannot calculate if its above that using Baby Step Giant Step as he explained previously. The puzzle keys are within a known range making it easy to get the private key after the funds has been spent. Your 42k address is IMPOSSIBLE to crack (at least not in this generation or next) even if you got all their public keys because their range are scary and larger than you can imagine.