Any type would be great, but you can go from easier to difficult in the roadmap:

1. Backup: just activate when main stream is not accessing the net and have a couple of customizable places to test. If using NAT, its not that complicated; if using DHCP only, then Automated renumbering would need to be implemented.
   • This type would need to consider ethernet connected links and also 3G modems to a USB port.
2. Classical Multihoming using ethernet ports or 3G modems to a USB port

Be sure to let people connect these additional links to any eero router.