I'm sorry, I just disagree. Your RP, your story, is not tied explicitly to one value or another.
An orc with 14 int, is smart. An orc with 16 int, is smart.
That +1 on your spell's DC, is not game breaking. Its just optimization. It has nothing to do with RP.
If you want to argue about what it does to the flexability of your OTHER ASI, then you are simply proving my point further. It is about the mechanical crunch. The optimization. It is not an RP concern.
Again, go nuts and have fun. There is a Tasha's mod right now, but if they make it into the 'official' version of BG3, I'll just have 1 more thing to mod out of the game.
An orc with 16 int is smarter than an orc with 14 int, though. That effects the roleplay of those two characters when it comes time to start rolling the dice.
I don't stop roleplaying when the dice come out. The character's rolls inform the success or failure of their actions within the narrative, therefore it is all part of the roleplaying experience to me.
Also. Why would you need to mod it out? Tasha's rules are optional. You'd literally just not use the option and get the same result as if it was never added in the first place.
Yeah, I am not sure why anyone would have to mod it out anyways? If they don't like it, all they'd have to do is not touch the ASI assigned by race once they pick their Race and Subrace? If it is a temptation, it is only one that has to be resisted once?
Edit: I typed this out before Scribe's reply was posted, I understand now.
Also I agree, a character with 16 intelligence is smarter than one with 14, so it would start to show in the rolls and therefor how I roleplay the knowledge. Like a character with 14 I might go "I remember reading in a book once that Kobolds often serve a dragon and by looking at their armor you can infer the type of dragon, so we should be careful cause I think they might be serving a black dragon." while one with 16 would likely have more specific knowledge and say it out like "These kobolds are using a South Eastern design in their armor, which is not native to here, and are using black and gold elements and a draconic symbol for acid, therefor I think that they must be serving a Black Dragon that has recently moved into this forest."