Currently, it's not possible to configure multiple IDP's in Qlik Sense SaaS.
This is confirmed by Qlik Support.
It would be great to have this option, especially the option to keep the Qlik Account login method active.
Use-Cases:
1. Only internal people are in Azure AD and have access to Qlik through this IDP.
External people can make a Qlik account and would be able to log in through their Qlik Account.
2. As a Qlik Partner, we support our clients.
Clients don't always want to provide an account in Azure AD because this brings licensing costs.
If we could configure an extra IDP, we could still use our Qlik Account to access the environment.