One of the parameters is the text to show. You could probably try using CREATE_VAR_STRING and then pass the resulting string there. No idea if Ctrl+C and Ctrl+V are supposed to work.
I do believe that the name is correct, it is just that for some reason the new MP weapons cannot be loaded in SP like before. Also thanks for the new list entries, I will add them.
It should work for all horses in theory, but I can test that one. Depending on the progress with the latest update we can also update the trainer soon and you can try it yourself!
This is a list of open source mods for Red Dead Redemption 2. Mods that are hosted here include their download link. Please leave a comment if you find a mod that should be included here!
https://github.com/thatoneguy650/DifficultyScaler (Download: https://www.mod-rdr.com/files/file/33-difficulty-scaler/)
https://www.mod-rdr.com/files/file/27-force-first-person-on-foot/ (Code in mod description)
https://github.com/ss-gnalvesteffer/red-dead-redemption-2-mods (includes Point Cloud Capture, Red Hot Redemption 2 and Ragdoll Redemption 2)
https://github.com/Saltyq/ScriptHookRDR2DotNet/blob/master/examples/ExampleScript.cs (Community Script Hook .NET by @Saltyq example)
https://github.com/Disquse/rdr3noclip (Noclip)
I have not looked into the variations too much, but chances are they are just outfits/skins for each model. Have you tried changing to one of these animals and then using our Outfit Changer to check the skins? That might be what you are looking for.
I can make it your personal horse and also allow you to stable it, but it will be reset once you reload the game, so not sure how useful that is. It at least allows you to bond with it, though.