Great to see this implemented as part of Fall release 7.3.
Vendor collaboration
Vendor collaboration has been extended to enable vendors to view and selectively maintain their own company information, such as contact information, business identification data, procurement categories, and certifications.+

The vendor can view and respond to RFQs, which includes the ability to receive and upload attachments. The collaborative interface allows the vendor to receive information about the awarded or lost bids.
In public sector configurations, RFQs can now be published and exported as entities via data management. This enables the data to be consumed and exposed in a customer-hosted public website.
A new workflow-supported process, Vendor onboarding, can facilitate the addition of new vendors to Dynamics 365 for Financial and Operations. The vendor is invited to register based on a signup request imported via entities or based on a request entered directly in Financial and Operations.
The registration process provisions the person representing the vendor with a user account that has restrictive security roles and then invites the user to register by completing a wizard-guided process. The guided registration process prompts for data ,such as contact information, business identification data, procurement categories, and questionnaire answers. The information entered by the vendor contact person is populated in a vendor request and after the information has been approved via a workflow process, a new vendor account is created.