As far as I understand it the Frontline is pretty saturated with drones. Heard it in a documentary that I cannot find, of course, but a quick search gave this article washingtonpost.com/…/ukraine-drones-russia-war-sk…:
The sheer number of drones means the battlefield is “almost transparent on both sides,” Nepal said, speaking from a makeshift base near the front line filled with parts for FPVs.
So yes seems to me as if it is a almost 24/7 thing. Maybe not over 100% of the Frontline, but at least in the most of it.
(I may have overestimated the meaning of hinterland… I meant like the 10km or so behind the front)