Okay less maintainable if it breaks but ... will it really break? I've done loads of miles on my bike with derailleur gears and that's not shown any sign of wear or failure.
Each chain and sprocket are subject to wear. Each sprocket of any bicycle must be replaced after a certain time. And the chain elongates and must also be replaced at some point. The chain also elongates on the Kwiggle, but the sprockets adjust to the elongation. Therefore also with the Kwiggle, the sprockets and the chain must then be replaced at some point. One of our first customers drives already 8,000 km still with the first chain and sprockets. This is quite much for a bicycle.