If you checkout the Observium project, he uses the MIBs instead of generic SNMP polls. Couldn't Nedi be made to use this approach aswell?
If this is impossible could a more generic approach to defgens be coded? Nedi already has support for a lot of hardware but not all models and lineups. Could defgen be modified with brand-centric defaults? Most values (broadcast/discards/ifaliases) are the same between models from the same vendor. Some differences may apply but they're not that many. Cut'n'paste often works between different models using HP Comware 5, HP Comvare 7, Huawei, Cisco IOS etc.