as i explained, to find a prime you got a better chance by testing a high nash k-value but on the other hand you have to test many more n-values.
have a look a the NPLB Drive #10 page on
www.rieselprime.de
every 1000n-range contains about 11000 candidates to test (by 300 k-values overall).
Drive #9B shows for only
one k-value different counts for candidates (between about 1000 and 130000) depending on the nash-weight.
although the n-ranges are different, you can see on both drives there exist ranges with more or less primes.
so the idea to test a wide k-range is best to find primes and as a side-effect you test all!