Normalizing Loudness LUFS of a whole track according to only a selected region

You’re describing two different tools. Most tools adjust a selection all at once to a setting. You sound like you want the effect of a sound engineer turning up and down the volume as the show progresses.

That’s an active compressor. Those are cool and highly desirable…and not fun.

Here’s a posting from someone trying to master compressor use.

Koz