I've been annoyed by the lack of imagination in heat sink extrusions. Also the pandemic. But this extrusion is pretty clever:
Perfect for spot-cooling on a PCB. When paired up, you can bolt a 40mm fan right onto the end. If you forego the clip, you can bolt four TO-220 parts to each heat sink. Here's a pic of four heat sinks in action:
With a setup like this, you can position either end of the wind tunnel against a hole in the enclosure.