Hey there,
This is not possible using the Cornerstone element and the Columnize feature is only for text. It is possible using the shortcode version and using the old content band and column shortcodes to structure the accordion items. Here’s a sample:
[accordion id="my-accordion"][content_band padding_top="0px" padding_bottom="0px"][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your text here[/accordion_item][/column][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your second accordion text[/accordion_item][/column][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your third accordion text[/accordion_item][/column][/content_band][content_band padding_top="0px" padding_bottom="0px"][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your text here[/accordion_item][/column][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your second accordion text[/accordion_item][/column][column type="1/3"][accordion_item title="Accordion Title" parent_id="my-accordion"]Your third accordion text[/accordion_item][/column][/content_band][/accordion]
Please note that you could easily break the structure by omitting brackets, quotes, closing shortcode tags, etc. Also, shortcodes must have no space between them like my sample. With that said, issues arising from the use of this structure would be outside the scope of our support because this is not the intended design/layout of the accordion and based on my example, it works provided that everything is complete.
Thank you for your understanding.