Thanks for yor response. This use I get but for it I don't need this plugin:
@unknownuser said:
problems with file size had numerous groups with the same geo.
One can make components out of groups and instances of groups this with native SU.
It's the making of components out of lines that I don't get much of.
So for your 'simple' best use you would have a lot of lines in your models which are not parts of components, and making them components with this would reduce your file size. OK. I do have a lot of groups which are not components, but next to no lines which are not parts of groups or components. For me the crux is when and what groups to componetize, just because it take time, even if it saves file space. Certainly if I have many of said group or I want component behavior from a group it would be best componentized, I don't need a plugin to do that. Rereading the thread I see the use implied of maybe wanting to populate a model with lines, componetize them and then subsequently edit the component which would then be in place wherever the lines were. If I can do this now with two lines instead of one, that is sufficient for me.