Files must be reloaded twice for changes to appear
When editing a file in another text editor and reloading it into RA Tools from File -> Recent, I need to do this twice for changes to appear correctly. I think that's a recent issue as I recently updated but have used the same workflow before and I never noticed this.
This is a bit inconsistent, but sometimes I actually have to change the text in the RATools editor and then reload in order for external changes to show up because it seems to refuse to reload an already-opened file.
I believe this is just a behavior of the WPF menu system. The submenu item for the recent script has three clickable areas:

Areas 1 and 3 exhibit the behavior of not refreshing the script. Area 2 does refresh the script. As long as I clicked in the darker highlighted area, the file consistently reloaded as expected.
Regarding the already open file: I would expect that to show an error dialog. File.ReadAllText should throw an exception. https://github.com/Jamiras/RATools/blob/22aa757e4fa1e8bb42ad32235da912803c59dcbf/ViewModels/MainWindowViewModel.cs#L242-L250
I believe this is just a behavior of the WPF menu system.
Bizarre. Is there no way to override that? Good to know anyway.
File.ReadAllText should throw an exception.
Why? Most decent text editors nowadays won't lock a file as it's being edited as far as I know, and I haven't had any issue with that workflow so far.
I was just responding to your comment:
because it seems to refuse to reload an already-opened file.
I read that as already opened externally. Perhaps you meant internally? The whole point of reload (Revert / F5) is to reload the already-opened file.
Which brings up a note to your workflow. Instead of using Recent Items to refresh the file, why not use Revert? It's one level higher in the menu. It's meant to reload from disk when you've made modifications in the editor that you no longer want, but it will also reload from disk when there are no modifications in the editor.
I use Revert now and it seems to work as expected, though I'd expect reloading the file to do the same thing.