Thanks Gustaf. One thing I like about bcrypt is that there is one variable, the work factor. 10-12 is a good value and you can increase it linearly. I am looking at argon2 from your commit and it requires: memcost, lanes, threads, and so on. You have to be a scientist to use it.
set r [::ns_crypto::argon2 -variant argon2id \
-password "1234567890" \
-salt "saltsaltsaltsalt" \
-memcost 12288 \
-lanes 1 \
-iter 3 \
-threads 1 \
-outlen 16]
Yup, argon2 won that competition but I like bcrypt's simplicity.