if any issues with adding new web app filter?

(from github.com/AllenHan5)

I wanted to implement a new authentication mechanism, say SAML.
From the possible solution I found from the Internet, it seemed adding a web app filter is a general way to go. Is there any implication if I add a filter to existing FESS web.xml?

Any guide about it?

(from github.com/marevol)
See web.xml for Fess.