I have a ubiquity edge router lite on Snap UFB. Yes you need to do the above if your firmware is older than Ver 1.5 In Ver 1.5 you can get it working from just the GUI. But note - that doing the above CLI commands will stop the firewall from working. And in Ver 1.5 there is a bug that means you can't reapply the firewall rules on an interface that is both a VLAN and has PPP. That bug has been fixed in Ver 1.6alpha.

Is your edge router the 3 port model? If so I can give you a copy of my config file. All you will need to do is edit it in Notepad to input your username and password. And then upload it. It already has the default firewall rules setup. So will work on Chorus UFB, Assuming that Spark use PPP for authentication.

And if you are setting it up yourself goto www.grc.com and click on the "Shields Up" link. This will run a port scan on your external IP addr so you can check that your firewall is working.

[edited to add]

Also has the required NAT rules ect. So it will just work.