Transpose row of irregular number of values to columns of matching indices

I have a Google Form featuring an ID number and a checkbox field capable of generating multiple choices, anywhere from 1 to 4.
I export this data to a Google spreadsheet.

When multiple checkboxes are ticked, the output goes into a single field with comma separators. I've created a second sheet in which I split that data using Split('TAB_REFERENCE!A1',"TRUE, TRUE) into a sheet that looks like this:

I now want to query that data to display ID numbers associated with each of the elements, to look like this:

I've tried multiple boolean OR statements in a filter, Pivot tables, and a half dozen bad ideas.

I can't use ArrayForumula because the element count varies. I know this is solvable but as my headline suggests, I can't even articulate the problem succinctly enough to get good search results. It's like a transpose of part of a row into columns of unique values with the index value displayed under the columns it matches. Help!