Using Kodi on Nvidia Shield with a HTSP steaming profile appears to be working and channel switch time is down to like 3 seconds, which is great and thanks for your help.
However using Live Channels with pass as stream profile is still fails. I can see a subscription to a channel in TVH with Input and Output figures changing constantly but the tv screen still displays a loading circle. Feels like a codec issue somewhere, anything else i could try?