Adding SSO to your Business Suite subscription is a smart upgrade because it gives your team one-click secure access to all tools. When you’re turning BAQs into live dashboards, SSO ensures users can instantly view real-time insights without multiple logins, improving workflow, security, and data visibility. This makes your BAQ-to-Dashboard process smoother, faster, and more reliable. https://epicforcetech.com/step-by-step-guide-to-epicor-implementation-for-business-success/

Proton Pass is great tool to enable and secure access. SSO in Proton Pass is awesome feature to allow organisation's users sign in with their protected credentials in their own organisation instead of creating new and separate credentials for Proton Pass.

Why not make Proton Pass a base for authentication also to other Proton ecosystem services like Mail and Calendar? That would enable organisation subscribers to automatically create accounts to all Proton services without separately and manually managing them in Proton?

Organisations tend to have processes and tools to manage user accounts internally. Managing Proton access manually is cumbersome. There should be a way to create Proton user accounts automatically (e.g. SCIM that Proton Pass already has a support for) and to allow standard based authentication (e.g. OIDC or SAML2) instead of separate credentials in Proton to access services. Proton Pass already has support for SSO in Pass Professional subscription.

Make note of other idea to add SSO support also in Business Suite: https://protonmail.uservoice.com/forums/953584-proton-pass/suggestions/50017167-add-sso-to-business-suite-subscription

SSO really is a critical feature for many businesses.
We would never use a mail service without it.

AD FS support probably makes more sense to implement than AD DS support though.

I wish that Proton would allow single sign-on for all payment levels. I am tired of having to sign into all the apps separately and it is not time consuming but rather a inconvenience. I would rather have the ability to open mail, sign in, then open pass or calendar or drive and be signed in. The fact that my account is already on my device, should carry over to the other apps. This should be available to ALL paying customers and not just business.

Add SSO, which uses the local domain controller to login into Proton Pass. This would make multi-user password managers more easy to integrate in to the ecosystem. Else each employee has a separate password for the Protonpass.
If possible, create Proton Pass account for selected accounts in the Domain Controller. This is to automate the process of making an account for each employee

This makes it easier for a business to add Proton Pass into its ecosystem. Current providers of such option with password managers are 1Password and KeepassHub.