Been around in Manchester for quite a while, though we do have a large Chinese community and China Town. There is a stall in the Arndale Centre which sells it, been there quite a while now though that's the only place I've seen it outside of China Town, can't say I'm tempted.
I tried it at the behest of my nephew and you're absolutely right, 3Ts - it's disgusting.
I note from the article that nobody seems sure quite how the drink developed. Well I can tell you. Somebody had a container of the said balls and were taking their tea break when they accidentally knocked the balls into their tea. Nobody in their right mind would have made the concoction deliberately.
Strangely enough I used to like tapioca when they served it at school, despite it being very much like frogspawn.
However, putting it in a cup of tea is just wrong. All kinds of wrong.