Not really ... the filter can't catch most of the ferrous particles that a magnet can catch.No magnets for me. The filter doing its job takes care of what a magnet does and does it better.
There are many moving componets in and engine that have basically zero MOFT ... those that are in the boundary & mixed lubrication realms, like cams lobes and rings.What the filter doesn't catch is mostly smaller than the lubrication film thickness.