diff --git a/src/main.ts b/src/main.ts
index d939cd45..9748ed60 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -92,12 +92,11 @@ const argv = args.argv;
 async function readOptionsFile(
   optionsFile: string
 ): Promise<ValidationOptions> {
-  const validationOptions: ValidationOptions = await readJsonUnchecked(
-    optionsFile
-  );
-  if (!validationOptions) {
+  const validationOptionsObject = await readJsonUnchecked(optionsFile);
+  if (!validationOptionsObject) {
     return new ValidationOptions();
   }
+  const validationOptions = ValidationOptions.fromJson(validationOptionsObject);
   return validationOptions;
 }
 
diff --git a/src/validation/ContentDataValidator.ts b/src/validation/ContentDataValidator.ts
index eadfa128..73ecf9fe 100644
--- a/src/validation/ContentDataValidator.ts
+++ b/src/validation/ContentDataValidator.ts
@@ -15,6 +15,8 @@ import { Content } from "3d-tiles-tools";
 import { IoValidationIssues } from "../issues/IoValidationIssue";
 import { ContentValidationIssues } from "../issues/ContentValidationIssues";
 import { ValidationOptionChecks } from "./ValidationOptionChecks";
+import { ValidationIssueFilters } from "./ValidationIssueFilters";
+import { ValidationIssueSeverity } from "./ValidationIssueSeverity";
 
 /**
  * A class for validation of the data that is pointed to by a `content.uri`.
@@ -183,9 +185,29 @@ export class ContentDataValidator {
         context.addIssue(issue);
       }
     } else {
+      const includedSeverities: ValidationIssueSeverity[] = [];
+      if (
+        options.contentValidationIssueSeverity == ValidationIssueSeverity.ERROR
+      ) {
+        includedSeverities.push(ValidationIssueSeverity.ERROR);
+      } else if (
+        options.contentValidationIssueSeverity ==
+        ValidationIssueSeverity.WARNING
+      ) {
+        includedSeverities.push(ValidationIssueSeverity.WARNING);
+        includedSeverities.push(ValidationIssueSeverity.ERROR);
+      } else {
+        includedSeverities.push(ValidationIssueSeverity.INFO);
+        includedSeverities.push(ValidationIssueSeverity.WARNING);
+        includedSeverities.push(ValidationIssueSeverity.ERROR);
+      }
+      const filter = ValidationIssueFilters.byIncludedSeverities(
+        ...includedSeverities
+      );
+      const filteredDerivedResult = derivedResult.filter(filter);
       const issue = ContentValidationIssues.createForContent(
         contentUri,
-        derivedResult
+        filteredDerivedResult
       );
       if (issue) {
         context.addIssue(issue);
diff --git a/src/validation/ValidationOptions.ts b/src/validation/ValidationOptions.ts
index d257c6a0..a182992a 100644
--- a/src/validation/ValidationOptions.ts
+++ b/src/validation/ValidationOptions.ts
@@ -1,3 +1,5 @@
+import { ValidationIssueSeverity } from "./ValidationIssueSeverity";
+
 /**
  * A class describing the options for a validator within
  * a `ValidationContext`
@@ -14,6 +16,12 @@ export class ValidationOptions {
    */
   private _validateContentData: boolean;
 
+  /**
+   * The severity of content validation issues that should be
+   * included in the results.
+   */
+  private _contentValidationIssueSeverity: ValidationIssueSeverity;
+
   /**
    * The content types that are included in the validation.
    */
@@ -37,6 +45,7 @@ export class ValidationOptions {
    */
   constructor() {
     this._validateContentData = true;
+    this._contentValidationIssueSeverity = ValidationIssueSeverity.INFO;
     this._includeContentTypes = undefined;
     this._excludeContentTypes = undefined;
   }
@@ -54,6 +63,23 @@ export class ValidationOptions {
     this._validateContentData = value;
   }
 
+  /**
+   * The severity of content validation issues that should
+   * be included in the result.
+   *
+   * By default, this will be `INFO`, meaning that all content
+   * validation issues will be included. It can be set to
+   * `WARNING`, to include all `ERROR` and `WARNING` issues,
+   * or to `ERROR` to only include `ERROR` issues.
+   */
+  get contentValidationIssueSeverity(): ValidationIssueSeverity {
+    return this._contentValidationIssueSeverity;
+  }
+
+  set contentValidationIssueSeverity(value: ValidationIssueSeverity) {
+    this._contentValidationIssueSeverity = value;
+  }
+
   /**
    * The content types that should be included.
    *
diff --git a/src/validation/Validators.ts b/src/validation/Validators.ts
index d8a17f11..4c1de991 100644
--- a/src/validation/Validators.ts
+++ b/src/validation/Validators.ts
@@ -458,6 +458,33 @@ export class Validators {
       );
     }
 
+    // Register an empty validator for NGA_gpm
+    {
+      const emptyValidator = Validators.createEmptyValidator();
+      const override = false;
+      ExtendedObjectsValidators.register("NGA_gpm", emptyValidator, override);
+    }
+    // Register an empty validator for MAXAR_extent
+    {
+      const emptyValidator = Validators.createEmptyValidator();
+      const override = false;
+      ExtendedObjectsValidators.register(
+        "MAXAR_extent",
+        emptyValidator,
+        override
+      );
+    }
+    // Register an empty validator for MAXAR_grid
+    {
+      const emptyValidator = Validators.createEmptyValidator();
+      const override = false;
+      ExtendedObjectsValidators.register(
+        "MAXAR_grid",
+        emptyValidator,
+        override
+      );
+    }
+
     Validators._registeredExtensionValidators = true;
   }
 }
diff --git a/src/validation/gltfExtensions/GltfDataReader.ts b/src/validation/gltfExtensions/GltfDataReader.ts
index 4ffc1112..30257628 100644
--- a/src/validation/gltfExtensions/GltfDataReader.ts
+++ b/src/validation/gltfExtensions/GltfDataReader.ts
@@ -1,5 +1,7 @@
-import { JSONDocument } from "@gltf-transform/core";
 import { Document } from "@gltf-transform/core";
+import { JSONDocument } from "@gltf-transform/core";
+import { Logger } from "@gltf-transform/core";
+import { Verbosity } from "@gltf-transform/core";
 
 import { BinaryBufferData } from "3d-tiles-tools";
 import { BinaryBufferDataResolver } from "3d-tiles-tools";
@@ -155,6 +157,8 @@ export class GltfDataReader {
   ): Promise<Document | undefined> {
     try {
       const io = await GltfTransform.getIO();
+      // Avoid warning "Missing optional extension"
+      io.setLogger(new Logger(Verbosity.ERROR));
       const gltfDocument = await io.readBinary(input);
       return gltfDocument;
     } catch (error) {
@@ -236,6 +240,8 @@ export class GltfDataReader {
     const resources = {};
     try {
       const io = await GltfTransform.getIO();
+      // Avoid warning "Missing optional extension"
+      io.setLogger(new Logger(Verbosity.ERROR));
       const json = JSON.parse(input.toString());
       const jsonDoc = { json, resources } as JSONDocument;
       const gltfDocument = await io.readJSON(jsonDoc);