Support › General › Save Google Analytics and website settings in Metabox Settings
I'm thinking to save website variables in Meta Settings. As example :
Google Analytics property
Path to PDF
Path to GPX etc
Is this recommended? Or does is slows down the code / site?
Yes, you can save site settings on the Settings page, just like the Theme Options and it does not slow down the site speed. See more on this article https://metabox.io/create-settings-page-customizer-options/