I remember seeing a chakirah once about the question of a Cohen leaving his seat to go duchen when he will have to cross in front of someone davening. Have you seen any teshuvos on this topic?
Matisyahu, Clifton, NJ
I'm not sure what Chakirah you're referring to, but when I asked you're question to Rav Moshe Sternbuch he mentioned the Machlokes as to why one is not allowed to pass in front of someone who is davening: either because it disturbs their Kavanah or because the Shechinah is in front of them (see Shulchan Aruch OC 102:4 and Mishnah Berurah). He said that if it is impossible for the Kohen to reach the Duchan without passing in front of a Mispalel, then he can rely on the first reason - assuming the Mispalel has his face covered by his Talis or is reading from a Sidur in which case he would not be distracted by the Kohen (see Biur Halachah, op. cit.).
Perhaps we can add that even if the Mispalel will be distracted by the Kohen passing in front of him, he is permitted to do so because the Kohen has a Mitvah mid'Oraisa of Birkas Kohanim.
Perhaps we can also say that Birkas Kohanim is Tzorchei Tzibur and therefore outweighs the consideration of the individual Mispalel.
See the Sefer Ishei Yisrael (29:13) who allows the Kohen to pass in front of the Mispalel if he has no alternative.
Kol Tuv,
Yonasan Sigler
This is not a Psak Halachah