I would never rent their garbage equipment. Not only is it garbage, but they lock you out of the majority of the router settings, as well as wifi settings now, with the wifi settngs not allowing higher connection speeds. You are also on the hook for the added cost of electricity that is required for the hot spot. There has also been flaws where people who connect to those hot spots have access to personal information of the customer.
I am happy to pay the extra $30 for unlimited, and use my own equipment.
I have 3 roku premiers, 1 roku tv, 1 xbox, 1 nvidia shield, windows 10 plex app, 2 android phones that have zero playback issues with plex and HD content. (most run direct play), I only use the shield for my 4K plex content as the roku's choke on the bandwidth requirements (non compressed, full 4K rips that can hit as high as 450Mbps to 650Mbps [avengers infinity war is the worst] during streaming with HDR and TrueHD 7.1 audio) Samsung tv app sucks balls (i think they quit supporting it), chrome and edge also suck balls because they are plagued with buffering issues with plex.
what is your plex server being ran on?