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/HttpRangeNotSatisfiableException.cs

@@ -0,0 +1,50 @@
+using System.Net;
+
+namespace EmbedIO
+{
+    /// <summary>
+    /// When thrown, breaks the request handling control flow
+    /// and sends a redirection response to the client.
+    /// </summary>
+#pragma warning disable CA1032 // Implement standard exception constructors - they have no meaning here.
+    public class HttpRangeNotSatisfiableException : HttpException
+#pragma warning restore CA1032
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpRangeNotSatisfiableException"/> class.
+        /// without specifying a value for the response's <c>Content-Range</c> header.
+        /// </summary>
+        public HttpRangeNotSatisfiableException()
+            : this(null)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpRangeNotSatisfiableException"/> class.
+        /// </summary>
+        /// <param name="contentLength">The total length of the requested resource, expressed in bytes,
+        /// or <see langword="null"/> to omit the <c>Content-Range</c> header in the response.</param>
+        public HttpRangeNotSatisfiableException(long? contentLength)
+            : base((int)HttpStatusCode.RequestedRangeNotSatisfiable)
+        {
+            ContentLength = contentLength;
+        }
+
+        /// <summary>
+        /// Gets the total content length to be specified
+        /// on the response's <c>Content-Range</c> header.
+        /// </summary>
+        public long? ContentLength { get; }
+
+        /// <inheritdoc />
+        public override void PrepareResponse(IHttpContext context)
+        {
+            // RFC 7233, Section 3.1: "When this status code is generated in response
+            //                        to a byte-range request, the sender
+            //                        SHOULD generate a Content-Range header field specifying
+            //                        the current length of the selected representation."
+            if (ContentLength.HasValue)
+                context.Response.Headers.Set(HttpHeaderNames.ContentRange, $"bytes */{ContentLength.Value}");
+        }
+    }
+}