We would like to be able to specify a break in the timing diagram. Its fairly common that some actions will take place in groups, but spread out over long periods of time. So having a diagram do something for 10 ticks, then skip or break, and resume at 200 ticks is a must have feature. There is already provisions for hiding signals in the diagram, so a skip could just simply hide all signals for a time specified.
Here is an example of skipping for some elapsed time
This feature has been requested a few times before and gotten no traction. See links below.
https://forum.plantuml.net/7582/compress-skip-time-in-timing-diagram?show=7582#q7582
https://forum.plantuml.net/12932/to-hide-a-long-non-interesting-part-of-timing-diagram
If this is implemented. I will make a promise to update the website with an example diagram