I actually pretty much hate the DexNav. I think it makes things too easy while being too time consuming. There is no such thing as a rare pokemon anymore with the DexNav once you've caught it once, but the process to getting even just a hidden ability pokemon is so slow, took me like 30 minutes earlier to get a HA Xatu, with the same really boring process over and over. I much prefer the immediacy of Friend Safari, never took me more than ~5 minutes to get a HA mon. I never felt excited when I finally got what I wanted through DexNav, I felt relieved I could stop doing the tedious process.
You're totally right though about the list. But more what I mean is you connect to the internet each day and get like 5(10?15?) totally random safaris that day like with Mirage Spots in ORAS, and the next time you connect the random ones replace the old ones. Add that to the friend code system as is.