My brain is a little fried but I've got my pulmo appointment tomorrow and want to make sure I'm properly prepared.

My existing plan:
List all symptoms
Ask for overnight oximetry

Any thoughts or recommendations from those who've been down this road? Anything I should keep in mind? Questions I should ask, etc?

Thanks in advance

I don't think you need any preparations.
A pulmonologist will do respiratory tests based on your symptoms and their experience and knowledge.
Most of their patients will have obstructive lung disease (smoking, asthma), some of their patients will have other forms of lung or vascular disease. A small minority have neuromuscular diseases.
The standard tests they will all do is for obstructive lung disease.
Most will also do tests for restrictive lung disease.
Many will not evaluate respiratory forces or respiratory muscle endurance.