Need ‘must-be-one’ and expanded=”true” on roll-your-own image trigger

Hi

I’d like to use Collapse-O-Matic ‘roll-your-own’ elements with images as triggers and would like to use two options with these images which only appear to work with the [expand] approach.

The first is the special class ‘must-be-one’.
The second one is the expanded attribute (‘expanded=”true”) which there seems no way of invoking in the roll-your-own format.

I’ve set up a temporary page showing some icons which, when clicked, reveal information.

We need to have the first item open (expanded) when the page loads. Then there must always be one visible as visitors click around. Is there perhaps a way to do this that I have missed seeing in the documentation?

The icons are in a horizontal list, each coded like this:

<li class="collapseomatic noarrow" id="sdg-01" rel="sdgicons-highlander"><img class="icon" src="..xxx.png"></li>

The target divs are coded like this:

<div class="collapseomatic_content" id="target-sdg-01" targclass="must-be-one">
<img src="..xxx.png">

Some text ...

</div>

I would appreciate your help if there is a solution. I have more applications for this if it can work.

Thanks,
Mike