While reading through the SNS proposals documentation I noticed few deadlinks:
See more general security best practices.
Therefore, the command to submit a proposal
sns make-proposal
404 → https://github.com/dfinity/quill/blob/master/docs/cli-reference/sns/quill-sns-make-proposal.md
use the specially-made
make-upgrade-canister-proposal
command
There might be other, just few links I clicked.
Hope that helps.