Hi Kevin Coles
Its hard to provide solution by imagining the visual based on text ..lol. But I can understand your constraint :-)
Have you tried this ?
While you are on the details sheet try Analysis >> Tableay Layout >> SHow Empty Rows (or Columns) depending upon your view. You can try this both, before union-ing 5 future years and after union-ing.
If this post assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution. Thank you.
There are a few online examples of working with nulls and dates taht I can provide here but if it's possible to upload even a small representation of test data, it would greatly help the community to assist further.
These are three great resources and I hope they resolve the issue but please come back to provide more details if you are still stuck.
Best of luck on your Viz journey