Hiding Variables the Email is viewed using Pubic URL

Your software
My Mautic version is: 4

Your problem

Is there a way to hide variables in Mautic when the email is viewed directly from the public address?

I would like to replace Dear [Title] [First Name] [Last Name], with Dear Customer when the email is viewed from the public URL.

Is there a way to achieve this?

Do you mean when someone is viewing the public preview?

E.g., https://mautic.yoursite.com/email/preview/$ID?

If I understand you correctly, then no.
(OFC you could create a custom plugin that removes variables in public previews)

What are you trying to do?

The public preview of an email isn’t really meant as some sort of publishable webpage. This is why you’re seeing those placeholders.