Especially when you obviously didn't read it in the first place.
Then you installed it wrong. I installed it a few months ago and it scaled everything just fine. (IIRC scalling the fonts is one of the options when you install the mod)
Unless something has changed, widescreen mod for IE games doesn´t offer font scaling.
For PS:T though, Ghostdog´s UI mod does this and it´s very likely you had it installed on top of widescreen one.
And from what I remember about Baldur´s Gate, it indeed scales "perfectly", but that does also mean fonts are much smaller, which may certainly be a problem on some monitors.
There is a font mod which addresses this, downloadable from here. It isn´t perfect, but it´s the only one I know about.