installing the OpenID Connect Provider App will not deactivate the existing Single Sign-On UCS Identity Provider with simplesamlphp, so you can use both in parallel.
Please be aware that they are different in their feature set:
Single Sign-On with OpenID Connect Provider
can only used for IdP initiated SSO
the transmitted information to SP in the Accecs Token is fixed and not configurable at the moment
Single Sign-On with SAML in UCS
will work with IdP initiated and SP initiated SSO
the transmitted information to SP can be configured in the SAML Identity Provider settings
Thank you very much for your answer.
We have a specific use for OpenId, so I’ll install it anyway as intended, but I will remember the difference between the two.