So, I'm going to use your updated US courses and US showcases files when it comes to adding US races to my own UK schedule.

I'm considering using the default "Chicago" track set-up for both Arlington Park and Belmont Park, as I think the Arlington layout in the game is more similar to Belmont than the Generic1 option, especially with the lake in the middle and the larger stands. Having had a quick look through your updated 3D files, I see that you've switched the "Louisiana" layout to Churchill Downs by default, which is definitely the best way to go. It also looks like you've switched the "Virginia" default to Pimlico, rather than Colonial Downs, which also makes sense.

I was trying to find mapped layouts that were close to some of the other major tracks in the US (other than the ones like Santa Anita and Aqueduct that are already there, of course), but haven't had a proper look yet.

Panther,

The New York track is closer to Belmont than any other track in the game. Chicago is about a 1 1/8 track with a mile chute.
The New York track has a 1 1/8 mile backstretch chute that Belmont has. The New York track is about 1 1/4 mile track that is closest to Belmont's
1 1/2 oval. It also has the big stands and the lake.

Chicago would be a good match for Aqueduct. Aqueduct is a 1 1/8 oval with a mile chute in the backstretch..
I grew up in New York and spent thousands of hours at both Belmont and Aqueduct and the above would be my choices.

I thought "Chicago" was modelled on Arlington and "New York" was modelled on Aqueduct (although I couldn't work out why Aqueduct was chosen ahead of Belmont for Mark to go to those lengths to create a course!). So, you would use "New York" as Belmont and "Chicago" as both Aqueduct and Arlington?

No worries

Yes, Chicago as Arlington and Aqueduct New York as Belmont

That is how I am using it. Also for all the 1 mile ovals I use Virginia. (Monmouth, Pimlico, Del Mar, Keeneland)
I also use Chicago for Saratoga and Gulfstream as both are 1 1/8 mile ovals also. These are the closest matches to the real
oval sizes... I will post some track diagrams and you will see.

Ah, that's great, thanks for your help with that. In addition to the other main ones that already have tracks in the game, that just about covers all of the tracks with the largest number of graded races.

Panther, Here are the diagrams

Also, use Wolverhampton as some of the dirt only tracks. Works well for bullring tracks too.

Also, I chose a track for every course now cause that's the only way the course portraits work for each one. So the courses in the file up for download will be changed (same name, same amount of courses, just new course files).

And New York is more like Aqueduct then Belmont due to the two dirt tracks.

So, does this mean you've now allocated a 'mapped' course to each of the US tracks, and that you're not using any generic ones now? Also, I'm not sure what you mean by the course portraits not working for others - surely, the course portraits are just photos that appear in the game?

Yes, no more generic courses.
And in order for unique course portraits to be used, the track needs files in the folder, not just a redirect. Will be easier to understand once they are available for download.

So, you can't add separate photos for courses that are only redirected to a generic course? I had assumed you could just put two or three photos in for any track. If you wanted to create 'smaller' tracks, I suppose you could just copy the files from one of the generic courses and add them to a named course.

Also, as mentioned by ghostzapper in another thread, you could probably do with dropping Beulah Park and Fairplex from your track list. As pointed out by ghostzapper, Beulah can just be replaced with Mahoning Valley, and you've already included Los Alamitos in place of Fairplex.

I was going to, but Fairplex was a default in the game and Beulah had some final races earlier this year. And I added in Belterra Park (not Mahoning Valley) to the game since that is replacing Beulah as the major Ohio track, although the license is going to MV.

I prefer using the Chicago track for Aqueduct because both are 1 1/8th mile. A 9 furlong race at Aqueduct starts in front of the stands.
The chute at Aqueduct is a mile not 1 1/8 like it is in the New York track. Belmont's chute is 1 1/8 so I use New York for Belmont.
All in the eyes of the beholder. Hopefully with the course editor we can make accurate tracks.

Have you figured out how to use the middle dirt course at New York track?

No, but I hope to figure it out once we get the course editor (I think it is just for show and not an actual piece of the track, like how Woodbine has the harness track on the way inside). Once it is figured out, I will do the same for Woodbine, adding in dirt, Belmont, making two turf tracks, Meadowlands, eliminating dirt (although that might be possible now...hmmm...let me go try that now haha), and any other tracks that have multiple tracks.

I'm guessing it's just for show as well. At least one of the Japanese courses has a hurdles track clearly visible, but there aren't any jumps courses listed for Japan.