Here's some late-night nitpicking for your pleasure. In the first episode of season 2, Major Briggs relates a vision to Bobby with the following introduction:

A vision I had in my sleep last night. As distinguished
from a dream, which is a mere sorting and cataloguing
of the day's events by the subconscious; a vision, fresh
and clear as a mountain stream, the mind revealing itself
to itself.

Which sounds great but makes you wonder why he's saying it in the first place. I think this bit of monologue is Lynch's way of retconning the fact that Cooper's "dream" in episode 1.3 isn't meant to be a dream but a vision. It's also a first indication that the black lodge might actually be a real place, rather than just another quirky part of Cooper's imagination.

It's obvious that a lot of Twin Peaks was basically invented as they went along, especially the black lodge mythology, which didn't even reach its full complexity until FWWM. Most of it came to fruition by the start of season 2 though, hence the sudden explosion of weird characters: the waiter, the giant, the Tremonds, etc... Season 1 doesn't really contain much in the way of the supernatural so I don't think Lynch originally intended to go that way.

In any case, this bit of text now clearly delineates what is dream and what is vision. Lynch even covers himself by adding the key part "in my sleep last night", completely paving the way for compatibility with Cooper's experience in episode 1.3.

But I also think that Lynch might have felt uncomfortable with the whole "dream sequence" on a more theoretical level. He knows that Cooper's "dream" is not how people dream in real life. Real dreams are not so explicitly surreal. They're mostly rather mundane and only seem weird at the edges. To the dreamer they make sense on a scene-to-scene basis. This is basically how most of the plot in Mulholland Drive unfolds, but also the (controversial) first half of FWWM. In fact, I think this is the only part in Twin Peaks where Cooper is actually dreaming.

The first black lodge visit is just a vision, a vision of Cooper's doom.