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/Internal/LockableNameValueCollection.cs

@@ -0,0 +1,9 @@
+using System.Collections.Specialized;
+
+namespace EmbedIO.Internal
+{
+    internal sealed class LockableNameValueCollection : NameValueCollection
+    {
+        public void MakeReadOnly() => IsReadOnly = true;
+    }
+}