I have the same issue with sound but when I get to one of these channels I use an external player that allows you to select a different audio stream if necessary. This can be mxplayer or extreme iptv pro i like the feel of smart iptv. That's why I'm sticking with it, but I do find some uk channels freeze. i have also recently set up kodi,using pvr simple client. This gives you the best of both worlds as you can select a different audio streams and since I set it up I haven't had a single freeze!
I have it in two android boxes at home. One is an h96 pro 3gb 16gb. The other one is a t95n (come to think of it, it could be a t95x - I'll have to check). This one has 2gb 16gb. i just followed the tutorial for setting up. I was using a build from Jayhawk media so I couldn't get the build to display the channels list but I downloaded the official kodi remote to my iphone and now I control it all from there. Even the program guide is displayed. And the best thing is I get no freezing at all on a any channel, even the hd uk ones. I'm happy!
I can confirm that with the kodi setup, if the channel has subtitle data, it can be selected and works correctly. having said this there doesn't appear to be as many channels with subtitles as there are channels with alternative audio streams. by the way, the English audio stream appears to be the 2/2 stream. (The dubbed audio stream appears to be 1/2). It is possible to set the 2/2 as default audio for "all media" on kodi, so now I've got most of the Spanish and polish package in English by default. I think also the portugal channels. I'll search other countries later.
here is a link for the guide I followed to set kodi up.