One more thing: orientation on both ridges is not problematic but can be on the passage between ridges.
Approaches on our side probably not orientationally demanding either (from Učje and Breginj to Božca is road anyway, from Kobarid along the ridge, don't know, maybe @igor.b can say). Descent on Italian side to Gumin is ok to Predola (how from there to the other side to Pers I don't know), further to Scuglielarsa (Gumina suburb) reasonably well marked. From Karman to north side to Ledisa (turnoff couple dozen meters after descent from summit then soon right down, poorly marked) can have snow in upper part even in May, I didn't need crampons (poles almost mandatory), can confuse orientation a bit of course. Then small issues a bit after Scric pasture, otherwise to Ledisa ok. Both approaches described here on hribi.net. Just from Ledisa of course not to Gemona but at junction before it right to nice little church we reach in about 10 min. From there right to Tacca pass and Pian di Tapou.
Problematic though can be connection between both ridges, it goes at least partly by road and through settlements: path 710, which is last (at least official and marked) descent from Stol ridge, goes north side to start point couple km further from Tam at border (Tanamea) south to Monteaperta. For latter don't know exact route cause haven't been there (maybe someone else). From Monteaperta probably to Lusevera then Pradielis, Cesariis then path 729 to Dolina saddle then further to bit before Tam za goro then to Lanež.
First connection: path 710 to start point which is few km on Terska side of Tam at border pass, from there left along main road to Ai Sorgenti (some 3-4 km). If I'm not mistaken correct me, there is some path along the road too, at least to start for Muzce or even to Ai Sorgenti but not sure.
At Ai Sorgenti then to Muzci village. There junction. Follow path 709 left (right path to Kadin). We didn't miss, path although under Muzci ridge and just a bit above valley gets real mountain character, all until after about 45 min we cross pass. From there as cut off - forest. After some 15 min we reach second marked turnoff to Kadin which we ignore and continue straight. Then after some 5-10 min we reach junction which I'm not sure is marked or not. Anyway mustn't miss it cause straight goes to Pušja ves (Venzone), left quite soon (no more than five minutes) we reach Pian di Tapou and small parking with info board. So can reach there by road from Ai Sorgenti (if someone wants to bring another vehicle up for return), but it's closed (at least last time I was there). Driving at own risk, stones on road (even some bigger ones), can extend to Forcella Tacca (again no entry sign) for those who don't mind undercarriage of their car.
As hiker though after arriving at Pian di Tapou to Lanež turnoff from mentioned parking onwards two options:
- along mentioned traffic closed road to Tacca pass. This path obvious, but less marked turnoff from it few bends before pass summit. When we hit it arrival to Lanež turnoff is 5-10 min matter.
- for second option from parking along road couple 100 m back direction (to Ai Sorgenti). If look carefully right we'll notice in forest signs (path 729) both for Lanež and Karman and High Gumin path (Alta Via Gemona). Follow them and after good 45 min we reach Lanež turnoff too.
This turnoff marked only with arrow on rock and especially in autumn due to leaves (personal experience) can be missable. But once found no more major orientation problems. Just need to watch to go a bit across Tam za Goro pasture to Lanež (not to Dolina saddle). Interesting then the start to ridge from Lanež summit. From summit go a bit further as if to other direction, but path after 100-200m turns, goes under Lanež summit and on to ridge towards Karman.
So, hope useful to someone. Let someone else supplement and correct if something wrong.