It's clear that one of the reasons given on BIP39 to allow a password is to make plausible deniability possible:
So we are not just talking about a simple account management using different passwords, but an adversarial setting where the password will make some funds inaccessible to an attacker. The greater the number of iterations, the harder the attacker's job.

You're technically correct, the best kind of correct

Yes, some bits will be filled randomly so we can "pick" the last word, it's not just a checksum calculation.

Yes, I'm the main author. The name is a natural one for a Rust project because we are talking about a cRUSTcean (also Rust's mascot, Ferris, is a crab) and it's also adequate in the context of Bitcoin where investors are compared to sea animals.

Krill is particularly important to whales but it's also the basis of the food chain of other sea animals. Krill lives in cold waters but if you want to hodl them for a long time it's better to store them frozen 

Compared to something like electrum being used offline there are perhaps three notable differences:
1) When using frozenkrill, the generated seed is encrypted with strong cryptography because the key derivation/key stretching algorithm (argo2id) has been created to withstand brute-force attacks. Any encryption/decryption will take a lot of cpu and memory.

On the other hand electrum uses a much weaker algorithm (just a password hash AFAIK for the disk database, other wallets may use something better like scrypt, but probably with a low number of rounds/RAM requirements and still prone to GPU cracking).

Most wallets will by default show the BIP39 seed which uses PBKDF2 with just 2048 iterations if the user selected a non empty password. This is also very prone to brute-force attacks.

By default frozenkrill will never show/print the seed, never store it with a weak encryption and only let the user access it indirectly for the signing of PSBT files

In practice these algorithm differences is the difference between an attacker taking one day to crack the wallet or million years.

2) frozenkrill allows and encourages the user to use keyfiles as part of the password (see the README for more information). This is something that only exists on advanced encryption systems like TrueCrypt/VeraCrypt that have been designed with a more paranoid threat model

Note: this isn't a flaw of these other wallets. None of them has been designed to let the seed be stored "online" after it being generated offline. All of them will strongly recommend the user to store the seed offline, specially in paper/metal plates.

3) frozenkrill is a CLI only, so it doesn't need a graphical system (like the X server in Unix systems) which let it run on very lean operating systems. This reduces the attack surface.

This is the first public release of our Bitcoin wallet focused on cold storage.

It's open-source, CLI based and written in Rust.

The goal is to provide a secure solution to generate private keys that can be stored in digital mediums (e.g cloud storage). It's an alternative to current-gen hardware wallets for some users that don't have physical security and stability.

It's beta but should work fine. All feedback is welcome.

Please visit our github page for more information: https://github.com/planktonlabs/frozenkrill

If you have any questions please ask.