diff --git a/lib/src/CmsBootstrap.php b/lib/src/CmsBootstrap.php
index 48f9a19f..98e0d044 100644
--- a/lib/src/CmsBootstrap.php
+++ b/lib/src/CmsBootstrap.php
@@ -278,18 +278,12 @@ protected function buildCv(): array {
    */
   protected function loginStandaloneUser() {
     if (!empty($this->deferredUserToLogin)) {
-      global $loggedInUserId;
-      if (class_exists(\Civi\Api4\User::class)) {
-        $userID = \Civi\Api4\User::get(FALSE)
-          ->addWhere('username', '=', $this->deferredUserToLogin)
-          ->addWhere('is_active', '=', 1)
-          ->execute()->single();
-        \CRM_Core_Session::singleton()->set('ufId', $userID);
-        $loggedInUserId = $userID['contact_id'];
-      }
-      if (empty($loggedInUserId)) {
-        throw new \RuntimeException("Unable to login as '$this->deferredUserToLogin'");
-      }
+      // Note: Standalone always has "authx".
+      authx_login([
+        'flow' => 'cv_cli',
+        'useSession' => FALSE,
+        'principal' => ['user' => $this->deferredUserToLogin],
+      ]);
     }
   }
 
@@ -308,8 +302,13 @@ public function bootBackdrop($cmsPath, $cmsUser) {
     }
 
     if ($cmsUser) {
+      $theUser = \user_load_by_name($cmsUser);
+      if (!$theUser || $theUser->name !== $cmsUser) {
+        throw new \RuntimeException("Failed to find Backdrop user ($cmsUser)");
+      }
+
       global $user;
-      $user = \user_load(array('name' => $cmsUser));
+      $user = $theUser;
     }
 
     return $this;
@@ -618,6 +617,13 @@ protected function ensureUserContact() {
         \CRM_Core_BAO_UFMatch::synchronize($GLOBALS['current_user'], TRUE, CIVICRM_UF, 'Individual');
         break;
 
+      case 'Standalone':
+        // Recall: We're looking at the edge-case where a "User" is defined without corresponding "Contact".
+        // On Standalone, the *UI* is slightly more effective blocking this edge-case. (But you can still get it via API...)
+        // In any case, UFMatch::synchronize() doesn't seem to do anything on Standalone. (Maybe b/c special uf-match
+        // dual-purpose schema?) But for now, there's no point complaining about "Unrecognized UF".
+        break;
+
       default:
         $this->log->error("Unrecognized UF: " . CIVICRM_UF);
     }
diff --git a/scripts/check-phar.php b/scripts/check-phar.php
index 2bd84fc9..b4519325 100755
--- a/scripts/check-phar.php
+++ b/scripts/check-phar.php
@@ -29,6 +29,7 @@
 assertMatch('lib/src/CmsBootstrap.php', ';JFactory::;');
 assertMatch('lib/src/CmsBootstrap.php', ';Drupal::;');
 assertMatch('lib/src/CmsBootstrap.php', ';drupal_bootstrap;');
+assertMatch('lib/src/CmsBootstrap.php', ';user_load_by_name;');
 assertMatch('lib/src/CmsBootstrap.php', ';user_load;');
 assertMatch('lib/src/CmsBootstrap.php', ';wp_set_current_user;');
 foreach (['lib/src/Bootstrap.php', 'lib/src/CmsBootstrap.php'] as $file) {
diff --git a/src/Util/UrlCommandTrait.php b/src/Util/UrlCommandTrait.php
index 3004d866..b6c6508b 100644
--- a/src/Util/UrlCommandTrait.php
+++ b/src/Util/UrlCommandTrait.php
@@ -91,7 +91,12 @@ protected function createUrls(InputInterface $input, OutputInterface $output, bo
 
       $cid = \CRM_Core_Session::getLoggedInContactID();
       if (!$cid) {
-        throw new \RuntimeException('The "--login" option requires specifying an active user/contact ("--user=X").');
+        if (empty($input->getOption('user'))) {
+          throw new \RuntimeException('The "--login" option requires specifying an active user/contact ("--user=X").');
+        }
+        else {
+          throw new \RuntimeException('The "--login" option requires an active user/contact, but they could not be detected in this environment.');
+        }
       }
       $token = \Civi::service('crypto.jwt')->encode([
         'exp' => time() + $this->defaultJwtTimeout,
diff --git a/tests/Command/HttpCommandTest.php b/tests/Command/HttpCommandTest.php
index d8455088..7ccd22bf 100644
--- a/tests/Command/HttpCommandTest.php
+++ b/tests/Command/HttpCommandTest.php
@@ -22,8 +22,15 @@ public function setUp(): void {
     $this->cvOk('en authx');
   }
 
-  public function testAuthorizedGet() {
-    $body = $this->cvOk("http {$this->login} civicrm/authx/id");
+  public static function getBootLevels(): array {
+    return [['full'], ['cms-full']];
+  }
+
+  /**
+   * @dataProvider getBootLevels
+   */
+  public function testAuthorizedGet(string $bootLevel) {
+    $body = $this->cvOk("http {$this->login} civicrm/authx/id --level=" . escapeshellarg($bootLevel));
     $data = json_decode($body, TRUE);
     $this->assertTrue(is_numeric($data['contact_id']), "civicrm/authx/id should return current contact. Received: $body");