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/Utilities/Validate-Route.cs

@@ -0,0 +1,33 @@
+using System;
+
+namespace EmbedIO.Utilities
+{
+    partial class Validate
+    {
+        /// <summary>
+        /// Ensures that the value of an argument is a valid route.
+        /// </summary>
+        /// <param name="argumentName">The name of the argument to validate.</param>
+        /// <param name="value">The value to validate.</param>
+        /// <param name="isBaseRoute"><see langword="true"/> if the argument must be a base route;
+        /// <see langword="false"/> if the argument must be a non-base route.</param>
+        /// <returns><paramref name="value"/>, if it is a valid route.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="value"/> is <see langword="null"/>.</exception>
+        /// <exception cref="ArgumentException">
+        /// <para><paramref name="value"/> is empty.</para>
+        /// <para>- or -</para>
+        /// <para><paramref name="value"/> does not start with a slash (<c>/</c>) character.</para>
+        /// <para>- or -</para>
+        /// <para><paramref name="value"/> does not comply with route syntax.</para>
+        /// </exception>
+        /// <seealso cref="Routing.Route.IsValid"/>
+        public static string Route(string argumentName, string value, bool isBaseRoute)
+        {
+            var exception = Routing.Route.ValidateInternal(argumentName, value, isBaseRoute);
+            if (exception != null)
+                throw exception;
+
+            return Utilities.UrlPath.UnsafeNormalize(value, isBaseRoute);
+        }
+    }
+}