I would like to point out a few things
Zamasu spread such that he grew past his timeline and went to another, there is a void between timelines, he definitely has low 1C range
Zamasu also is omnipresent within his range as he "grows" by fusing with the space-time, essentially becoming one with what he fused with, this, his durability and his range gi hand in hand, because if he spread across a 5d distance, he is essentially a low 1c construct. Upgrading his range, upgrades his durability.
As for Zeno, it should be noted that, anime Zeno isn't the bloodlusted psychopath that the manga Zeno is, and while he still takes his anger out on the universe (keyword beinG UNIVERSES) he has never harmed an angel, and we KNOW he can use his erase in such a way as to choose to selectively spare people even when erasing Soave time structures as we saw in the ToP. Secondly, it Zamasu only siread through out the universe 7, destroying not the just the universe, but e en the higher realms like the neutral zone, how OWN home, all the angels and even the GP within his timeline makes ko sense no matter how you try to spin it, if he only stopped at all the universes, yea , there may be an argument there, but then his own home too, and also the angels, who he always spares? Even the GP, leaving himself utterly alone? This point MORE to the fact that Zamasu had corrupted the timeline
Now, Whis sensed Zamasu in the present and he and Beerus noted that something happened on the future that had an effect on the past , "future" and "past" here being timelines, finally we see his face appear in the past, just before he's nuked, meaning he did arrive, he was sensed and was seen , he arrived, but was nuked before he could do the same with the present timeline
Basically imho, my argument boils down to this
As an infecting entity fusing with and becoming whatever he spreads to, low 1c range and durability will scale, a low 1c construct won't have 2c durability
As for the possibility that his range may not scale, there is more proof to him affecting the timeline itself then otherwise, no matter how one tried to spin it or stretch Zeno's tendency for wiping out universes, it makes zero sense to destroy his own home, his grand priest, guards, angels and everything else I'd Zamasu only infected ONE macrocosm.