Your understanding about the tool is correct. If necessary we can consider an enhancement in the future. But I would like to know the expectations.
When an input is a straightline, you can insert vertices at a specified distance and leave the last segment shorter. But when an input is not a straight line, but a polyline with some vertices, these existing vertices would have to stay; this means that the distance has to be measured from the starting vertex of each segment and may leave a shorter segment before the ending vertex of that segment. Is that the desired result? For example, a polyline has three vertices, i.e. two segments. Let's say the first segment is 120 meters and the second 270 meters. For a 100 meter desification distance, would you expect to get 5 segments in the order of 100, 20, 100, 100, 70 meters?