Until recently, OWASP actually recommended 310,000 as the default number of iterations. But that seems to have nearly doubled over the past week. Even Bitwarden's message on Mastodon does mention that the initial plan was to set the KDF iterations to 350,000, but then they decided to go with 600,000.
BTW via Bitwarden site
just a heads up
Though the risk involved in rotating your encryption key does not exist when changing KDF iteration count, we still recommend exporting your vault beforehand
#CoSoSec
https://bitwarden.com/help/what-encryption-is-used/#changing-kdf-iterations