Grant Strugnell posted this unusual FKT route:

The Hume and Hovell Walking Track stretches over 440km between Yass and Albury, in New South Wales, Australia.

The track allows walkers to rediscover the route of explorers Hamilton Hume and William Hovell on their expedition to Port Phillip in 1824.

Mt Taranaki is a popular mountain hike in New Zealand's Egmont National Park.  There are many FKTs on Taranaki, and even a website devoted to recording these:  https://taranakispeedrecords.wordpress.com/

The Munda Biddi is a long-distance trail stretching more than 1,000 km from Mundaring in the Perth Hills to Albany on Western Australia’s south coast. Its name means “path through the forest” in the Noongar language. The route traverses the Darling Range and southern forests, passing through eucalypt bushland, granite outcrops and coastal landscapes on a mixture of purpose-built singletrack, forest tracks and roads.