Hi. Congratulation on making one of the most useful Sketchup plugins.
I have an idea to make it twice time useful ...simply by adding inverse function. So it could not only trim SU geometry, but also extend it using the same logic in picking 2 point lines, faces or 3 point faces...
Even more useful would be possibility to select a few faces, or curved surface as an "edge" for trimming, or extending.
It would be powerful feature.