Are you asking to have the PingPlotter instance settings written into the .PNG file when you save it? There are a few ways to read your suggestion here, and I want to make sure we understand what you're after before we create a new change request for it.
Just as an FYI, if this is what you're asking is to have the trace interval displayed, you can figure out the trace interval from the currently displayed information. In particular, the time *range* is displayed, along with the number of samples displayed in that range. Using those two variables, you can determine the trace interval that is being used to collect the data.
Please help us better undersatnd your request / need here. We *do* appreciate the feedback, but want to make sure we don't do the wrong thing.