How can I add text to the time tooltip only at certain points for chapter markers?

[klammm]

My goal is to append text to the time tooltip only at certain points for chapter markers. Similar to this example but with the time tooltip and text side by side at the chapter marker points.

For example,

• at time 0:50: The time tooltip will show 0:50 Hello instead of only Hello or 0:50
• at time 1:45: The time tooltip will show 1:45 Hello world instead of only Hello world or 1:45

Here's a screenshot of what I'm trying to achieve. This is the format I need for the time tooltip:

[klammm]

Discussion being held in #8315