Hello,
The left option is working fine, you can test it running this simple sample:
<?php
require_once 'classes/CreateDocx.inc';
$docx = new CreateDocx();
// custom options
$latinListOptions = array();
$latinListOptions[0]['type'] = 'lowerLetter';
$latinListOptions[0]['format'] = '%1.';
$latinListOptions[0]['left'] = 1;
$latinListOptions[1]['type'] = 'lowerRoman';
$latinListOptions[1]['format'] = '%1.%2.';
// create the list style with name: latin
$docx->createListStyle('latin', $latinListOptions);
// list items
$myList = array('item 1', array('subitem 1.1', 'subitem 1.2'), 'item 2');
// insert custom list into the Word document
$docx->addList($myList, 'latin');
// save the Word document
$docx->createDocx('example_createListStyle_1');
But it seems the problem is that you are not setting the list style to the list of the HTML. The customListStyles option doesn't assign a style ID to a list, you need to use the wordStyles option. there're some samples of this property on this page:
https://www.phpdocx.com/documentation/introduction/html-to-word-PHP
Or you can use DOCXCustomizer to change the style ID of a list:
https://www.phpdocx.com/api-documentation/docxcustomizer/customize-docx-Word-documents-PHP
Or use the addList method instead of HTML if you want to have more control:
https://www.phpdocx.com/api-documentation/word-content/insert-list-nested-Word-document-with-PHP
About inline and block types we just explaining that could be useful for some replacements, not your exact case.
Regards.