Quote - So I guess I should rephrase my original question: "What's the big deal with gamma correction in the context of how my final render will appear?"

There are a number of factors to consider when creating a good image.

Colour processing is one such factor. It is the base factor, really. Poser uses linear colour information to process colours. If you want to Poser to process the colour correctly, then give it linear data.
Lighting is tied in with that.

I'm not sure how else to say it.

All the clever rhetoric about how everyone's monitor is calibrated differently and how great images were produced prior to knowing about Poser's need for linear data is irrelevant to that fact. Granted that the information might have been more gently presented, but one cannot discount the fact that Poser uses linear data to process colours.

Do with that information what you will. I'm not saying anything about whether your image quality will suffer from not using GC... I'm merely stating a bald fact: Poser uses linear data to process colours.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks