I like this idea of getting a trail done quickly. What’s the point of taking your time just to look at scenery? Get out there, hike it fast and get back to civilization sooner. The less time spent outdoors, the better.
Here is a video of Gear Junkie hiking the MN Border Route Trail. Normally a 5-7 day backpack. He did it in about 30 hours.
Here’s Gear Junkie’s website that details two other long hikes he completed in around 24 hours.