I have this problem all the time.

Like when I'm in a business meeting and I want to sound calm and calculating, but also purposeful and authoritative.

My voice breaks my immersions!

Thankfully you said it not me, I don't see why everyone's worried about this, if you have followed anything the lord Todd Howard has said There is quite a bit of dialogue for the protagonist. I'dd say Modders who are crafty enough to make their own characters or quests are crafty enough to deal with a simple issue such as dialogue.

It will be about as immersion breaking as the numerous waifu mods that use Japanese VO's ripped from other games. That is to say - none at all.

With 13,000 lines of dialogue available to each protagonist, I can imagine that modders will string together responses that suit the needs for their modded followers.

It means that it's a bad quest mod...

Modders could either use voice actors whose voices have similar tones to Brian Delaney and Courtney Taylor, or take voice samples from their dialogue in the vanilla game and mash them together to make unique lines of speech.

I find the use of the term '"immersion" to be immersion breaking...

Until we are 100% sure that a modder cannot add PC conversation, isn't this a complaint premature?

Indeed! HAHAHAHA