I have 5 x60 and 2 x90 Decos in my home.  One of the X90s is in the basement where the cable internet and main modem is located, and the others are scattered around the house and backyard.  Everything works great, but I am wondering what the purpose / benefit of identifying the MAIN deco.  Currently of course, the x90 in the basement beside the modem is the MAIN.  The app suggests i can change the main Deco to another unit... does this work if the others are not connected to the modem?  What would be the benefit of changing the main deco to another?  Would doing so make the "main" a stronger wifi / throughput source?