Apparently, I should not be enjoying my Firestick Max as much as I do. I kind of like the advertisements, how else will I know about things that Amazon would like to promote. As long as they don't require me to watch an advertisement before I can run an app, I can't see a problem. I would have thought Apple would try to promote it's Apple TV Plus product, along with Apple Music and Games, including their other hardware products.
I also use wifi on all my Firestick Max devices. Channels DVR reports greater than 400mbs and 4ms latency to the server. I don't think duplex matters much for normal streaming. They all connect using wifi 6, which I think must do something to help with interference. At least I seldom have any pauses or glitches when streaming. I do occasionally get some interference on my TV antenna, which causes Channels DVR to have some problems.
I also have added 128Gb to my Firesticks, but it did take me some time to find memory that was fast enough to work reliably. And I don't totally trust it to work long term, but so far it has been great for more than a year using Channels DVR.