Got at least one data fetching method working; turns out, we can't use a patched LogicStack to get the data

Vendor/EmbedIO-3.5.2/WebApi/WebApiController.cs

@@ -0,0 +1,73 @@
+using System.Security.Principal;
+using System.Threading;
+using EmbedIO.Routing;
+using EmbedIO.Sessions;
+
+namespace EmbedIO.WebApi
+{
+    /// <summary>
+    /// Inherit from this class and define your own Web API methods
+    /// You must RegisterController in the Web API Module to make it active.
+    /// </summary>
+    public abstract class WebApiController
+    {
+// The HttpContext and Route properties are always initialized to non-null values,
+// but it's done after creation by a runtime-compiled lambda,
+// which the compiler cannot know about, hence the warnings.
+#pragma warning disable CS8618 // Non-nullable property is uninitialized. Consider declaring the property as nullable.
+
+        /// <summary>
+        /// <para>Gets the HTTP context.</para>
+        /// <para>This property is automatically initialized upon controller creation.</para>
+        /// </summary>
+        public IHttpContext HttpContext { get; internal set; }
+
+        /// <summary>
+        /// <para>Gets the resolved route.</para>
+        /// <para>This property is automatically initialized upon controller creation.</para>
+        /// </summary>
+        public RouteMatch Route { get; internal set; }
+
+#pragma warning restore CS8618
+
+        /// <summary>
+        /// Gets the <see cref="CancellationToken" /> used to cancel processing of the request.
+        /// </summary>
+        public CancellationToken CancellationToken => HttpContext.CancellationToken;
+
+        /// <summary>
+        /// Gets the HTTP request.
+        /// </summary>
+        public IHttpRequest Request => HttpContext.Request;
+
+        /// <summary>
+        /// Gets the HTTP response object.
+        /// </summary>
+        public IHttpResponse Response => HttpContext.Response;
+
+        /// <summary>
+        /// Gets the user.
+        /// </summary>
+        public IPrincipal? User => HttpContext.User;
+
+        /// <summary>
+        /// Gets the session proxy associated with the HTTP context.
+        /// </summary>
+        public ISessionProxy Session => HttpContext.Session;
+
+        /// <summary>
+        /// <para>This method is meant to be called internally by EmbedIO.</para>
+        /// <para>Derived classes can override the <see cref="OnBeforeHandler"/> method
+        /// to perform common operations before any handler gets called.</para>
+        /// </summary>
+        /// <seealso cref="OnBeforeHandler"/>
+        public void PreProcessRequest() => OnBeforeHandler();
+
+        /// <summary>
+        /// <para>Called before a handler to perform common operations.</para>
+        /// <para>The default behavior is to set response headers
+        /// in order to prevent caching of the response.</para>
+        /// </summary>
+        protected virtual void OnBeforeHandler() => HttpContext.Response.DisableCaching();
+    }
+}