Merge Sub-Item Parent Summary Timeline with Item Timeline if no Sub-Items Present

On our team’s primary board, we have both items and sub-items. We currently have our sub-item timelines summarized on the parent item, but if an item has no subs, we need to create an additional Timeline column. This results in two side-by-side Timeline columns, where it would be helpful to have one merged column that either displays the sub-item summary timeline, or the items timeline if no subs are present, in one column.

I reached out to support and this is not currently possible with either a column or an automation.