Printed in Sainsmart TPU. PTEG as predicted wasn't durable enough. I didn't have any nylon but I had just received some TPU so gave it a try and surprisingly it works really well.
Wanhao Duplicator i3 V2
Hrm... Interesting. Break any blades (or worse) due to the frame bending too much?
Not so far - it would be better in semi flex but I increased the Z height of the frame to make it a little stiffer but all the mounting hardware reduces the flex a lot.
I've banged it into quite a few things that would have fractured my PETG frame and had no breaks.