The path from Nogara bivouac to the junction with the path leading from Mangart Saddle towards Mangart is an ascent across meadow and scree. There is no particularly demanding spot on the path, only a few cables below Nogara bivouac, but nothing special. If you ascend to the top of Mangart, then the "harder" parts on the Slovenian or Italian path will follow.
I don't know why you would want to avoid Via Italiana (ferrata). It is a sporty via ferrata equipped with cables from entry to exit (except in the middle on the grassy part I think there aren't any, but I really don't remember

, in any case they are not needed there

). It allows enjoyable climbing with beautiful views, while you can be clipped to the cable throughout the rocky section. Towards the top the via ferrata is quite exposed, but not difficult in terms of technical difficulty (this is of course a subjective assessment). If you already have experience with via ferratas, then I recommend the ascent via this one. Of course assess your own abilities!
Descent via Plazje on dry ground I do not recommend (scree ...).
I also attach a photo of Mangart into which I have entered the approximate (!) route of the path. The position of the bivouac is marked with a blue X (this is accurate). With a red line I marked the usual path, with pink the approximate course of the via ferrata: the entry into the wall is marked correctly, but for the upper part I do not guarantee that I made a completely accurate drawing, certainly the exit is somewhat left of the lowest point of the ridge). I also drew the transverse path that is used if going to the via ferrata from Mangart Saddle (in this case it is not necessary to descend all the way to the bivouac).
(Mangart is photographed from the slopes of Ponce)