Hi, I used 2 gpx files of my acquaintance's who hiked one part of 605 in Aug 2020 and the other one in Oct 2021, respectively. According to him, he stuck to the marked route. 

As far as I can see, the last changes to the path in OSM were made in Jun/Jul 2020 (and some even in 2018), which is before the gpx's I used for reference. My corrections according to the gpx also align with Strava heatmap and the latest ortophoto (where the path is visible) you provided me with before. 

If you believe that some changes are incorrect, please feel free to correct.