What would you like to be added:

Changes in the label files in the features.d directory are now propagated every sleep-interval. I'd like to have it so that NFD worker watches the features.d directory and runs the labeling procedure on every change.

Why is this needed:

We have a use case where a workload requires additional node configuration on top of an extended resource (device plugin). The workload is structured so that a container requests an extended resource and is nodeSelector limited to nodes with a special "configuration complete" label. With the default 60sec sleep duration, there is an additional 1-59 sec delay before the workload is scheduled to a node. For the labels to appear quicker to nodes would make them more convenient to control scheduling.