:wow Wowww, now you are able to do filter to draw lines.
Does it mean, if you continue on this path, will you be able to do triangle, square, hexagon, pentagon, stars, circle, etc... and so on?
Because that would be a "revolution" in the GIMP software, that's the thing that all beginners are complaining, or people coming from the other software, that GIMP does not have tool to made shapes in just a click/tool/filter visible directly on the canvas...
A question about that "Equal Pi", why do you limit the number of lines to 12?
15 or 30 would be a better number for limitation, because with a 12 limitation it will be hard to do everything in relation with 360 degrees (for example 45 or 90 degrees), 15 on the other hand is just fine as a minimum, a bit like the Ctrl+Shift when drawing, it does 15 degrees constrain
Symmetry Paint limit at 100
I'm sorry to disappoint but this plugin is based on Gimp's Kaleidoscope filter with 12 being the limit of blind segments. Everything internally this plugin is limited Kaleidoscope AKA gegl:mirrors. I think what you want is possible but it would involve a mathematician and c programmers help.
I will study more to see if I can get GEGL to make separators. Though I am doubtful. It would have to be based on an existing filter.