Never really used NSX-T with Veeam as yet but it should work fine.  I would double check the segment in NSX and also not sure if useful, but this link might help -

Veeam Datalabs with Nsx-t - CloudOasis

• Isolating a virtual lab router interface ensures that experimental environments remain separate from production systems.
• This separation prevents unintentional disruptions to live production traffic.
• Configuring the router to respond only to designated traffic maintains network integrity.
• Using cleaning nc scripts can automate the process of clearing any test configurations post-experiment.
• It is crucial to implement strict access controls to prevent cross-environment contamination.
• Monitoring traffic between the isolated interface and production ensures compliance with security policies.
• Regular audits help identify any accidental routing of production traffic to the lab environment.
• Employing cleaning nc procedures can help in resetting the lab environment, ensuring a fresh start for each session.
• Documenting network configurations and changes enhances troubleshooting and accountability.
• Automated alerts can be set up to notify administrators of any unauthorized traffic between the environments.
• Using VLANs or subnets can provide an additional layer of isolation for the virtual lab.
• Ensuring that the virtual lab environment follows best practices for network hygiene maintains overall network health.