Security of private key(s)

I found a lot of resources on the web about securing private Key(s) such as adding a passphrase, HSM etc. but, the case of private key(s) generated by LE client seems to be different as the process is automated. Do I need to take any steps to secure the private key(s) generated by LE or leave them as they are?

Server private keys are usually not protected by a passphrase, because that would require to have it somewhere else in plaintext or the server wouldn’t be able to restart it self in case of e.g. a power failure or any other reboot situation / unexpected crash.

Thanks for your response.
I am not talking about specific measures, but, do we need to take any such measures with LE generated server private keys? I have mentioned passphrases, HSM as examples.