Show selected and all the other categories after filtering

Hello there,

The filter works fine, and does an incredible job. I have a question / problem, though.

On the linked page, after selecting a category, the whole product category filter disappears (since its not finding the other categories, which does make somewhat sense) – but I’ve put the “OR” logic, so I would like to select multiple categories, which is not possible after selecting the first.
Also, I want to show what category is selected, since the pre-filtered links are going to be all over the page.

So basically, I want the category filter to be static in order to be shown always, and just select the checkboxes without removing any options.

I’ve tried disabling dynamic counting and all the other options, but as soon as I filter the first time with the category, the filter just displays the subcategories.

The page I need help with: [log in to see the link]