The reason Feronikeli and other Kosovo clubs have minimal UEFA r it is not easy to ascertain which clubs in the then Serbian top flight were in what is now Kosovo. However I can scarcely believe that none did: being all part of the former Yugoslavia.
On the contrary, it is very easy to find out that FC Prishtina and FK Trepca played in the Yugoslav top league. The former are in the Kosovo premier, the latter in a Serb regional league as they came from the Serb quarter of Mitrovica. After Kosovo's split, a new club, KF Trepca play in the second tier in Kosovo having taken over the former ground of the Serb club.
No sign of Feronikeli which was founded in 1974 and thus have no top flight history and no European experience until this season thus they will inevitably have a low ranking. They may well improve as time goes on but don't be fooled by the relative strength of the Kosovo national team who are almost exclusively made up of players from outside the domestic league.
I therefore don't think it was too much of a shock that they were eliminated by TNS who in the last five European seasons (to date) have won 8, drawn 4 and lost 8 European games