Is there a difference in how Microsoft Edge reading mode and safari reader display their content?

In some cases, they might differ as both web browsers use different web engines. For example, PDF iframes may differ depending on the browser you use.

No there isn't a lot of differences between them because there all browsers that support different things

Safari only supports Apple company

Microsoft only supports windows 10

The reader display they use the same coding method just with different styles

and ways of using a program