Thanks for your question and welcome to the Optimus community forum.
At this time, it does not appear there is a way to highlight zeros outside of the fields on the top and bottom of our clusters. We will talk to our developers about this and ask them to make this possible.
For anyone interested in highlighting zeros in its current iteration, this setting can be enabled through cluster chart settings under the “Highlight Zeros” as shown below:
When there are updates made to this setting we will update this post.
Optimus Futures Support