@Yos 

Did not see the settings of metered connection. As I knew, R480T+ backup WAN will be offline unless primary WAN down. It's normal. This is what 'backup" means.

The router seemly cannot meet your second demand. Whether WAN2 come to help, it's only decided by the WAN1 status(down or up). 

You maybe can disable link backup, just use load balance. Enable Bandwidth Based Balance Routing on port(s).  Make two WAN work together but WAN2 pass less traffic.

Note:

• 1. To enable "Bandwidth Based Balance Routing", please first configure WAN bandwidth on the "Network"->"WAN" page.
• 2. The WAN port traffic ratio will be equal to the preset bandwidth ratio of each WAN port after "Bandwidth Based Balance Routing" of the port is enabled.
• 3. If the bandwidth ratio of WAN1 to WAN2 is set as 2:1, the traffic ratio of WAN1 and WAN2 will be approximately 2:1 after "Bandwidth Based Balance Routing" of WAN1 and WAN2 is enabled.

@Andone I think the problem is:

1. The load balance not able to generate dynamic ip from WAN-2 that cause the ip keep showing 0.0.0.0/link down/disconnect/offline....so I change to static ip with manual ip input.

Since I make create ip, then the load balance start to work.

2. I also un-tick efficient router on load balance menu.

Now the fail over works and the load balance (with ratio) also works.

Noted about 2nd demand not possible.

@Andone What is the tick "efficient router" impact on operation?

@Yos 

Do you mean "optimized routing" ? With Application Optimized Routing enabled, the router will consider the source IP address and destination IP address (or destination port) of the packets as a whole and record the WAN port they pass through. Then the packets with the same source IP address and destination IP address (or destination port) will be forwarded to the recorded WAN port. This feature ensures that multi-connected applications work properly. Used for some application like online payment.

And you can use dynamic IP for two WAN ports, but just cannot make two WAN work at the same time if you still want to use link bakcup. You still can use load balance that make the traffic pass two WAN ports based on the bandwidth ratio. 

@Andone Thank you for helping me to understand, wish you all the best

i almost have the same problem which is the failover does not work. but mine is slightly different. the router fails over to Wan2 (backup) but only after about 30 secs. what I did was to run a continous ping on google through cmd. then disconnected Wan1. i can then see a request time out in cmd. then, after about 30 secs, it goes online again (can ping google.com). what setting do i need to set so that i will have a seamless failover? 

@Andone Thank you. I have used your suggestion and you're right. it's still not seamless as I would have expected but at least the waiting time is shorter. Another learning for me is when WAN1 goes backup, there will still be time out episodes. i compared the downtime between policy routing and load balancing, and policy routing is 10 seconds faster (got the average on 3 tests), Again, thank you for the assistance.

@HCarigma Just to add up....under policy routing some application will stuck longer (before switching) if you tick "optimised routing". So I also untick that one.

Me too...prefer policy routing than failover. 

   I wish I had bought this 5 years ago.  I live on top of a mountain far from the ISP (Frontier) and am using a NVG443B router/modem.
I normally get 700KbPS when downloading and when I first hooked up My TL-R470T+ I did not have to even tell it to do load
balancing and it used wifes modem and Mine and I was getting 1.5 to 1.7 MBps !!!!   

  I am sorry that I just do not understand all the jargon but I keep messing around with settings and nothing is bringing 
back the ability I had as I am back to 700Kb download now and I keep restoring the R470T to factory settings
and its not doubling my DL speeds like it did when brand new.   I have not stuck a pin into the actual R470 to reset it that way.

 Any help with this would be much appreciated as it helps so much with money as leaving the computer on for two days
to download a Flight Sim Mod/terrain is really expensive and when it was double speed, it was awesome.

 Mike Kelly
Retired E-2 Electrician and FFII/EMT