My thoughts on that article? Not specifically Chan, but my own thoughts ...
All stems from the problem of considering nirvana as something
Then one gets into the quandry of what does one do, in fact, what can one do, to get to something which is uncaused? So people say, "Oh, just do nothing!" ummm, well it is true on one level, but 99% of people will mislead it.
But I think that:
Duhkha arises as the result from the presence of the defilements which are the cause.
That's a clear dependent origination.
Duhkha ceases due to the absence of these defilements.
The process of removal the defilements is the path, and the cessation is nirvana.
Duhkha and origin are dependent arising, the mundane.
Cessation and path are dependent cessation, the transmundane.
Now, nirvana is "not caused" but not in the sense of a thing which has no causes, but in the sense of it is the absence of result due to the absence of cause. In order to remove the cause, it isn't just a case of "do nothing", because for most people this just leaves their original defilements intact. Rather, one engages in actions which actively remove the defilements.
We could liken it to driving a car. If we have our foot on the gas, then we move on, travelling on highway samsara. Our aim is to stop, which is a kind of "doing nothing", unconditioned by the motor driving us forward. However, the best response is to actively take the foot off the gas, removal the main cause, and putting it on the brake.