It would be awesome to have a block that becomes powered when it's in a lazy-loaded chunk, and unpowered when in an entity-processing chunk (or a signal that can be read with a comparator). I think this would make a good friend to the temporal stability sensor from Ars Controle.
Use-case: Qther taught me the wisdom of using a lazy chunk detector to shut off farms that produce item entities so you don't crash the server. Existing solutions are either bulky or noisy, and I think it fits with the theme of Ars Controle and its Tempral Stability Sensor to have a block like this.