I've been using mConnect lite with an iPhone and an Oppo UDP203 until very recently as a "toe-into" the streaming waters. mConnect provides a very nice interface for surfing several streaming (hi-res) services and casting.
I had contacted Oppo support previously who still responds (wow!); they indicated Oppo UDPs do NOT render; as such, hi-res streams may be down-sampled (not bit-perfect) by the rendering mConnect platform. Oppo does have their own APP which does remote "control" their UDP; however, it is dated with no streaming services functionality.