The client side crypto is only as strong as the server side security. If, as an example, I get DigitalOcean to reset the password on the VM (or any other way to

The client side crypto is only as strong as the server side security. If, as an example, I get DigitalOcean to reset the password on the VM (or any other way to access the web servers) then I can simply add another line to the JS to post the plaintext data to a server of my choice. Game over. You should use PF if you trust them not to be compromised (hacked or be malicious) and not to backdoor the software. It shouldn't hinge on the client side crypto.