public void AddExtraDiffStore(
    string id,
    ModelStoreBase store
)

Public Sub AddExtraDiffStore(
    id As String,
    store As ModelStoreBase
)

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.DC;
using DevExpress.Persistent.BaseImpl.EF;
using SolutionName.Blazor.Server.Controllers;

namespace SolutionName.Blazor.Server;

public sealed class SolutionNameBlazorModule : ModuleBase {
    public SolutionNameBlazorModule() {
        Description = "XAF Blazor Demo module"; }
    // ...
    private void Application_CreateCustomUserModelDifferenceStore(object sender, CreateCustomModelDifferenceStoreEventArgs e) {
        var application = (XafApplication)sender;        
        // Main store: Database-based user model differences
        e.Store = new ModelDifferenceDbStore(application, typeof(ModelDifference), false, "Blazor");        
        // Add extra file-based store for shared customizations
        string extraDiffFile = Path.Combine(
            Path.GetDirectoryName(Application.ExecutablePath),
            "SharedCustomizations.xafml"
        );        
        if (File.Exists(extraDiffFile)) {
            e.AddExtraDiffStore("SharedCustomizations", new FileModelStore(extraDiffFile));
        }        
        e.Handled = true;
    }
    // ...
}