2 ISP and 2 routers ,+ mesh

[laptop]

I never know where to post. Hope this is the correct place.
I have 2 ISP, 2 modems and 2 Asus routers.
Can I use the ASUS program with both routers?
What I am wanting to do is add rt-ac86u b1 to a T-Mobile gateway as an extension/ mesh. I would like to Asus program if possible but I can not see the second router in the software. I understand it's connected to a different ISP. But how do I do it?
Second router is rt-ax86. Not that is would matter but it is easier to identify.thank you

 

[degrub]

What is the purpose of the second ISP ?

 

[laptop]

It is hopefully temporary as I am looking for a better service provider. My cox service is terrible. So I am wanting to verify the other ISP service before dropping cox

 

[dosborne]

Rather than a complex setup for testing, why not just connect one, run some tests, connect the other, run similar tests, then decide which is better? Otherwise, you can setup both, and just change the default gateway to point to one or the other.

 

[laptop]

thank you, I am having issues with both ISP's staying connected when I am using it as speeds are all over th eplace from 6 to 400 Mpbs. Strange for it may be the area that I am located in . Hills and a lot of trees.