The realistic scenarios of nuclear war occur as an escalation of some large scale conventional conflict.
If you take out enemy airbases and nuclear capability, then you can use tactical nukes (or, more likely, you already started using them) to win that conventional war and achieve whatever goals you had in it. There's no reason to invade - just as with Japan in 1945, you can subjugate a country without invading it
That would seem to indicate that reducing civilian loss wouldn't be a likely result of targeting improvements. After all, we ended the war in Japan by intentionally inflicting civilian casualties to force surrender. Seems likely future leaders would make the same calculation. So, the strategy would likely involve destroying the opponent's ability to retaliate add then start massacring civilians until you get an unconventional surrender.
Carpet bombing failed to undermine morale both in Britain and Germany. Here's an anecdote: the village priest when I was little lived through WW II and was a pacifist, a serious one, but he had a vicious hatred for Bomber-Harris, as he was called.
If you take out enemy airbases and nuclear capability, then you can use tactical nukes (or, more likely, you already started using them) to win that conventional war and achieve whatever goals you had in it. There's no reason to invade - just as with Japan in 1945, you can subjugate a country without invading it