If you have Nvidia Shield or android 4k boxes, use something else other than stbemu I suppose. Something that isn't limited by the Portals max settings.
If you're gonna buy something for olds people who are not tech savvy, MAG or TVIP that uses a Portal is the most simpliest configuration you can have. With android/stbemu you can get more out of your box (Netflix, apps so on). Never buy an Nvidia shield if you're just gonna get it for IPTV...