You're grasping so tightly at straws it's embersssing.
How does having a silent PC in mods equate to no dialogue check? Like, seriously. You're just making nonsense up at this point.
If you're making a quest mod for 4, just do what you've been doing the entire time. It's not going to be seemless, but it wasn't ever in the past games since suddenly all npcs lacked voiced.
You could have generic things said, but claiming this is going to be a jarring experience when it has been a problem since oblivion is just ignorant whining.
If I hop on steam and play any OB mod, I go from fully voiced npcs to those who have me reading all lines, and it works. It's not a jarring experience because I am able to distinguish between the base game and a user created add on.
I'm not expecting anyone to record their voice, and it doesn't take away from the experience at all. It isn't making the transition less seemless because there's no way a guy working alone can voice an entire mod without putting in tons of works.
If anyone is expecting the average mod maker to provide voice acting, you're being unreasonable. It's been this way for over a decade. The PC will be silent this time, and it's going to be different than in the base game, but it's no different than npcs suddenly becoming mute.