Hi @navdušena.
From Col to Čavn with all stops it took us, say, 10h. But with all effective walking about 8h. It's true that at Col it says Path along the edge, which follows, 6h, but of course with a visit to Sinji vrh and all peaks and sights that you certainly can't miss and capture on camera, it stretches to at least 8h. Especially if you walk "by nose", and due to lack of markers from Podrta gora towards Sinji vrh, you stray among the rare houses in that part of the trail. We mistook Knafljič's markers for the markers of the Angel's Path, which features a spiral livened up by the sun. At the top, to which we also "fought" midway with bulls and other cattle, we were around 9.30h, so after 3h. Then we continued along the edge all the way to Predmeja, where it's time for a proper and deserved snack, then another good hour of walking to Koča na Čavnu, where we slept. We could have gone to both Modrasovca, but we lingered, so we left that area for another time. Next day to Kucelj-1236m, all the way to Veliki rob. Followed a long but interesting descent to the village Vitovlje, where we also saw the famous church from 1361. To Šempas there was still a good half hour of walking on asphalt surface, which is quite tiring.
We recommend this route to you, especially if you're looking for solitary and scenic paths enlivened by flowering plants, views of the Slovenian hinterland and on nice weather also the Kanin mountains chain, and historical remains from Napoleon's time.