I dont have either router but you sound like you could use a fresh pair of eyes on this. I found a review/write up on one of the routers here

I skimmed it and found that OpenWRT is overlay to Qualcomm Wi-Fi SON (Self Organizing Network) and that there is a paradigm of ‘master’ and ‘slave’ mesh nodes. In his set up he used the b1300 to be the ‘master’ and then preceded to add ‘slave’ or secondary nodes from b1300. I think it may be one of those ephemeral auth session where requires the whole thing is done at one time and requires flash to reset or start over.
My suggestion is to figure out how to negociate use of Qualcomm SON… lulz.
Goodcloud and Astro-Relay from gl-inet are my second suggestion. That does require setting up for that (agents) and will probably still require knowing Qualcomm SON.