Hi - most of these attributes that you've mentioned are not part of the server class. Nor are they data that can normally be discovered from querying a server. VLAN & Subnet are not attributes defined on a typical server OS so there is nothing for Discovery to query since that data doesn't exist as elements on the device.
IP addresses (1 or many) are discovered on servers and are tracked in both the singular IP field: ip_address on the CI record and if there several IP's they can be recorded in the IP Addresses table cmdb_ci_ip_addresses - which has a 1-to-many relationship to the CI record. But the cmdb_ci_ip_addresses table does not have a designation / flag or way to denote an IP is a "Backup" or "Management" IP. So while the multiple IP's may exist on a device and be discovered, those that your business may reserve as a backup or management IP, the SNOW cmdb doesn't have a way to know how your allocated purpose of each IP. Similarly, there is no consistent, standard query on a server for the "backup" IP, etc. hence Discovery can't deduce and record which IP is for what purpose.
Servers that are members are cluster can be discovered. A machine that is a member of a cluster is recorded via CI relationships and the cluster identifier/attribute can be tracked on the CI records. You can see these attributes on the CMDB_CI_SERVER record:
Hope this helps a bit??
