Mathematically not possible with 2 diplomats in 10 or less years, but I understand your point.
I believe the posts I was referencing weren't promoting a "+100 with everyone in X years" outcome, but an ouctome of being able to improve relations with somebody nearby at a faster rate than +2/mo.
And I agree, why does distance matter for everything but improve relations? I'm glad they're fixing this though because I'd rather not think of how they'd change ae to compensate for it.