They are are stored encrypted on your computer if I’m not mistaken

Honestly I wouldn’t expect Signal to try and take care of this

PSA: We’ve received questions about push notifications. First: push notifications for Signal NEVER contain sensitive unencrypted data & do not reveal the contents of any Signal messages or calls–not to Apple, not to Google, not to anyone but you & the people you’re talking to.

Doesn’t this mean there is nothing to log? You got me confused