Thank you! My counts seem to indicate that all assets, including fighters, background, and UI are still rendered at 1080p. (The lack of UI up-res isn't surprising, considering the game relies strongly on flat art there rather than rendering.) I appreciate your help in the thread!
After mulling it over for a little while, I've decided not to add games like this one to the list. (That is, they've had Pro support announced, but no improvements can be detected.) This is driven by the initial purpose of the thread, to serve as a guide to tangible game benefits for new and future Pro owners. The title, after all, is "games with PS4 Pro enhancements".
A compromise suggestion was made, to include claimed Pro games but mark them somehow versus those whose improvements have been confirmed. In the end, I think that ends up being superfluous. Lists of all games with announced support (regardless of release status or confirmation) are available elsewhere. And I'll continue to list potential candidates in the "please post info and shots" portion of the first post, so that serves much of the same purpose. Furthermore, past experience has taught us that even public announcements of features by devs might not be reflected in the released game.
My ultimate goal is complete clarity in the data presented. I'm sure no one thinks the list should include unpatched PS4 games. Yet any game which looks and runs the same as on standard PS4 is functionally identical, whether or not it is tagged as having "Pro support". The distinction isn't meaningful, and including such games seems it would only impair the usefulness of the list.
(Note that this doesn't mean World of Final Fantasy, UMvC 3, etc. are off the list forever. Even if they never get patched again, there may be enhancements already in place that just haven't been detected. But until we have proof of those improvements, I don't want to assume.)