That's because with Optik TV, it really depends on where your location is. Each house gets a certain amount of stream in HD and SD. It sounds like that your house can only receive two HD streams at the same time. It can't be helped unless TELUS impro...
Not only is Onavo good with counting data usage, it also includes data compression. Also, with regards to data, I suggest you going on a plan with more data first, then scaling back down when your usage is normalized.