https://travelmapping.net/hb/showroute.php?r=srb.b035&lat=43.290768&lon=21.822722&zoom=13The grade-separated road from east of Merosina to A1 exit 50 is signed as B35 and should replace the old routing.
OSM is no longer indicating B35 through Nis. I did not check if that's right but can only report from my field check today:
Heading A1 southbound, road 158 is indicated at exit 49. Only road 35 is indicated at exit 50, i.e. no A nor E number. Road 35 is indated leaving the grade-separated section just east of Merosina since the road is ending here. However, there are signs in place indicating A4 and E80 heading westbound, i.e. where the road is ending
That's all confirmed by OSM except of the E numbering since OSM does generally not indicate them. GSV is still from 2014.
E80 is not signed on concurrency to B35 till B38 where I headed north. B35 is also rarely indicated, so, ignore
I'll travel A1 northbound and A4 eastbound (Skopje - Nis - Sofia) next week. I will report if I spot anything in addition