- Add comprehensive custom fields table for Device, Interface, VRF, and IP Address
- Include API examples for custom field creation
- Document working vs non-working API filters for NetBox 4.4
- Add workarounds for filters that don't exist (ASN by device, L2VPN terminations by device)
- Update VRF interface assignment to show IP-based VRF membership
- Add virtual_ip custom field for anycast gateway support