If some of the menu under F4 match your request. Then you can set VTOY_DEFAULT_IMAGE to F4>xxxx as follows:
{
"control": [
{ "VTOY_DEFAULT_MENU_MODE": "1" },
{ "VTOY_FILT_DOT_UNDERSCORE_FILE": "1" },
{ "VTOY_TREE_VIEW_MENU_STYLE": "1" },
{ "VTOY_SORT_CASE_SENSITIVE": "0" },
{ "VTOY_MENU_TIMEOUT": "15" },
{ "VTOY_DEFAULT_IMAGE": "F4>Boot the 1st local disk" },
{ "VTOY_MAX_SEARCH_LEVEL": "max" },
{ "VTOY_FILE_FLT_ISO": "0" },
{ "VTOY_FILE_FLT_WIM": "0" },
{ "VTOY_FILE_FLT_EFI": "1" },
{ "VTOY_FILE_FLT_IMG": "0" },
{ "VTOY_FILE_FLT_VHD": "0" },
{ "VTOY_FILE_FLT_VTOY": "0" },
{ "VTOY_DEFAULT_KBD_LAYOUT": "PORTU_BRAZIL" }
]
}
{
"control": [
{ "VTOY_DEFAULT_MENU_MODE": "1" },
{ "VTOY_FILT_DOT_UNDERSCORE_FILE": "1" },
{ "VTOY_TREE_VIEW_MENU_STYLE": "1" },
{ "VTOY_SORT_CASE_SENSITIVE": "0" },
{ "VTOY_MENU_TIMEOUT": "15" },
{ "VTOY_DEFAULT_IMAGE": "F4>Boot the 1st local disk" },
{ "VTOY_MAX_SEARCH_LEVEL": "max" },
{ "VTOY_FILE_FLT_ISO": "0" },
{ "VTOY_FILE_FLT_WIM": "0" },
{ "VTOY_FILE_FLT_EFI": "1" },
{ "VTOY_FILE_FLT_IMG": "0" },
{ "VTOY_FILE_FLT_VHD": "0" },
{ "VTOY_FILE_FLT_VTOY": "0" },
{ "VTOY_DEFAULT_KBD_LAYOUT": "PORTU_BRAZIL" }
]
}