My bedroom/lounge/bird room is just big enough for Tachyon to fly around with about 20cms to spare from wingtip to wall (he cuts it close!), on occasion he will clip himself on the window (I think this is when he tried to land on the top of the net curtain which isnt strong enough to hold him) but ive installed that fake double-glazing plastic which essentially makes a tight drum over the window glass, an inch or so away from it .. much safer to crash into a bouncy plastic 'drum' rather then the window glass! He just bounces off it and continues flying.
I wondered if maybe you could rig up a rectangle of wood the size of the TV screen and stretch some of this clear plastic over it, you could still see the TV but it would become a bounce-able surface instead of a hard one. You could even adjust the bounceability depending on how much you heat the plastic with a hair dryer (this is what causes it to shrink and pull tight to make the double-glazing effect); heat it a bit less than the instructions say and you'd have a more bouncy surface because it would have more give.
Check around for the best price, but heres an Amazon link just to show you the product: [ame=http://www.amazon.co.uk/DOUBLE-GLAZING-DRAUGHT-INSULATION-WINDOWS/dp/B004L9QMJO]DOUBLE GLAZING FILM DRAUGHT INSULATION KIT WINDOWS 6sqm: Amazon.co.uk: DIY & Tools[/ame]