here example:
1.) if we have 1 transaction with remarks:
privatekey up to 128 bit : with nonce up to 128 bit -> lattice attack will show privatekey
2.) if we have 100 transaction with remarks:
privatekey up to 2**20 bit : with nonce up to 253 bit -> lattice attack will show privatekey
3.) if we have 480 transaction with remarks:
privatekey up to 2**10 bit : with nonce up to 254 bit -> lattice attack will show privatekey
4.) if we have 10 transaction with remarks:
privatekey up to 2**200 bit : with nonce up to 240 bit -> lattice attack will show privatekey
For 256-bit ECDSA with 8-bit leakage, I guess 50 (even 40) is enough.
source:
https://crypto.stackexchange.com/questions/98323/help-breaking-ecdsa-with-biased-nonces