Deneb (Vega-Lite Power BI) - Conditional Tick Mark removal?

Deneb noob here & working with a user who wants to see if tick marks can be removed where there is no label in deneb?

We also want to keep the max amount of gridlines possible.

Before

After

I tried using the conditional labels/located in the documentation, but could not get my expression to respect the labels in the chart above.