knowing and understanding are not always the same thing
if he is hotspoting the Roku , he is not 'streaming' on the phone
this is the key 'factor' to the situation
watching phone video stream on the TV is 'casting' or 'mirroring'
watching a roku channel using the phone as a wifi hotspot is entirely different
cabling a roku ? to the phone is not going to reduce the amount of data used to watch an HD video stream
if he is using the roku to watch Hulu
he can use the hulu app on his phone to watch a 480p stream at reduced data useage and 'cast' that to the TV with an adapter at the TV
is there a roku app ? for phones ? which might help
his phone plan is a key in this situation
and the only thing he has said is that he has a 15gig hotspot data useage, and he is trying to eliminate hotspot useage
if he has unlimted 'on phone' no hotspot use
he needs to stop using the roku, and stream it on the phone
