(As it is based on TxText (or a fork) maybe it isn't that difficult to add rendering on athens ?)
It should be not difficult. In Twisty end rendering on canvas is just 1% of code (or less).
I plan to adopt it for Bloc. And for this I will need Athens. And I think Bloc will simplify it a bit. TwyTextMorph implements similar concept of Bloc design which can be used directly.