You can set { "VTOY_DEFAULT_IMAGE": "F2>" } to set F2 browser as the default menu entry.

INSTALL/grub/grub.cfg

@@ -2318,8 +2318,11 @@ if [ -n "$VTOY_DEFAULT_IMAGE" ]; then
         
         export timeout
         export default
-        
-        if [ "$vtHotkey" = "F4" ]; then
+
+        if [ "$vtHotkey" = "F2" ]; then
+            unset timeout
+            vt_browser_disk
+        elif [ "$vtHotkey" = "F4" ]; then
             ventoy_localboot
         elif [ "$vtHotkey" = "F5" ]; then
             ventoy_diagnosis