In another post it is stated "There are specific cases where an application will also use multiple connections, such as certain download tools." Please tell me which download tools use this feature. Also tell me if its possible to combine 2 internet connections to share their speed.
If that's not possible, can the router detect the fastest of the 2 connections and prioritize that connection? I'm looking for true load balancing, not just picking a certain connection per device.
Another question, the 2 connections are different ip ranges, one 10. the other 192. does that matter?
None. An application running on an end device would never know about the 2nd line.
Not possible.
You can use sticky routing to stick specific connections to specific interfaces, but it won't add the speed. So 50 Mbps + 100 Mbps isn't 150 Mbps, it's just 50 + 100. The only possibility for so-called link aggregation would be https://www.astrowarp.net/
Not possible. You can try to give the better connection a better rating in the multi-wan routing: Multi-WAN - GL.iNet Router Docs 4
That's not load balancing, it's aggregation and only supported by AstroWarp yet.
If it is a flint 2 with two wan ports, you may look into port bonding.
Though my knowledge is very limited on this one, and also if there is something about the rfc scope, for example i don't know if both port ends has to support LAG ports or the rfc it uses, you may want to look into luci-proto-bonding or wait for a newer openwrt release, i readed recently on github they added DSA support for it which make the luci-proto-bonding rendurant, also one thing with the DSA change is that you don't need ip addresses unlike the luci-proto-bonding plugin for luci.
Its a gmt 3000 with 2 ports, 1 wan 1 lan. It also has a tethering USB port, which I use. The Wan port can convert to Lan. I suppose I could use the USB tether plus the WiFi or Ethernet inputs for this?
Not sure if that works, i don't think it does since that is a unusual setup, i don't think bonding works on the tether interface.