Trip report link https://oslosti.no/jotunheimstien-fkt-df25f1670949 (which includes links to downloadable GPX files).
I planned to do the FKT from Oslo to Galdhøpiggen in one big push. In less than three days. That was a completely uninformed guess. I knew people usually hike the trail to Gjendesheim in 11-17 days, and I was going 50 more kilometers over the mountain to the top of Gjendesheim. Needless to say, my initial plan got scrapped pretty fast when we realised how gnarly the trail was. The 400 kilometers of trail was everything from nice singletrack to rocks, swamps and bushes. Lots of fun! I reached Gjendesheim and completed the Jotunheimstien in three and a half days (83h 54m 10s) which is the Fastest Known Time on the trail. The previous known time was around seven days. After that we encountered a storm between Glitterheim and Spiterstulen. When we came down to Spiterstulen, to the base of Galdhøpiggen, we had to wait out for the storm and go for the summit when the storm cooled of. We lost around six hours. We reached the summit of Galdhøpiggen in 104h 39m 44s which is the Only Known Time for that trail. The FKT was a fully supported attempt and wouldn't be possible without the help from the crew of: Hans Kristian Smedsrød, Patrick Stangbye, Erika Wollner, Tyler Jones, Mads John Thomseth, Paul Ogier, Audun Nystad Bugge and Peter Dannevig.