I really don’t think the problem with the descriptive writing in Deadfire is the style. It’s the content.
Having just reread a bunch of the narration in BG and the non-dialogue text in PS:T, the big difference is that they’re usually describing things that are happening to you/inside your head. When you get description, it’s describing how you feel something or remember something or realize something etc... It’s typically relevant to your character.
In POE and Deadfire the description is usually only relevant to the NPC being described, so who cares?. But that’s not style, which is standard fantasy schlock. For example, I think Deadfire’s prose works just fine when you’re using your watcher powers to read an NPCs memories in conversation. I agree that the “he makes a meaningless hand gesture and scratches his ass” stuff is pointless.
tl;dr I reject the idea that descriptive text is the problem. Where these writers often go wrong it’s in what they choose to describe. That said, this shit is easy enough to skip.
No, the problem is both the style and the content. Contrary to what the writers of both T:ToN and PoE seem to believe, PS:T does not have purple prose. Its descriptions are concise and to the point. BG's prose is more flowery, but it's limited to the chapter transitions, so it never becomes a chore to read.
Compare Deadfire's description of that dwarf:
to Planescape: Torment's description of Deionarra, a ghost and one of the most important characters of the game:
Unlike Deadfire, where you get two paragraphs describing a character's smile in autistic detail (even though the portrait already shows him smiling through wrinkled skin), the writing in PS:T is content to mention only the things that would be immediately apparent to someone seeing Deionarra for the first time: her beauty and her posture, with the more flowery language ('ethereal breeze') used sparingly and with the important purpose of conveying her ghostly nature.