There are two scenarios that this request comes from:

1. I often create multiple tabs within a Lucidchart diagram to illustrate concepts around the same subject. I want to be able to reference a specific tab within the diagram, so that I don't have to create several individual diagrams for each concept I am explaining. 
2. When viewing a Lucidchart diagram on a wiki page, the tabs are only visible if you mouse over the chart - most of my colleagues miss this. It would be nice if the tabs always showed rather than hiding on mouse out. But, if I had a tab number to set it to, then I could at least get my readers to the right Lucidchart tab. 

Possible solution

The "Edit Lucidchart diagram" modal supports selecting Tab 1, 2, etc. This renders the Lucidchart doc with that tab selected.