Should be able to sideload Netflix apk (mobile version) and various others you have listed. The last I recalled that Z9X is able to support up to 4K content since the Widevine CDM level is 1 with a HDCP support of 2.2 - meaning support 4K up to 60fps.
Anyway, I won’t install these streaming apps on the UHD3000 because I have other dedicated streamer like NVidia Shield TV 4K and Google TV Chromecast to do that.