GL.iNet AR300M and load management

[Technoweenie]

So, customer service doesn't seem to have any answers.

I'm trying to set up a phone and a hotspot (USB tethered with wifi disabled) as WAN devices, through a powered USB hub, and have installed the proper libs for EasyTether on the router, and app on phone and have that working great.

Now I'm looking at adding the hotspot as another tethered WAN device, and am curious if anyone has experience in how they're load balanced, or tips in setting up.

Theoretically, I also have a 3rd device from a completely different carrier. If I could leverage 3 carriers and 3 systems that'd be amazing. Even in areas with crappy service, ie 1-2mbps, if they're all working they should give me at least 3-6mbps, OR, provide service if one device or 2 devices has signal/service but others don't.

I'd like this as seemless as possible, in a permanently installed mobile configuration, so I can drive wherever and have service/coverage in as many places as possible, without worrying where I'm going.