double lines - find/erase them? / work-around?

Hey there!
after a year of use, I was able to help myself through many “ups and downs” by videos and the try-and-error method. However, I am now stuck… When I create a sketch, it often happens that I draw lines on top of each other, like placing points at certain distances where I can dock later. If I don’t trim these lines, duplicated lines overlay at these points/distances, resulting in errors on our milling machine. The current solution would be to trim all lines in a drawing individually. So trim, if line disappears, step back, next line.

I thought I recently found a solution using the “Projection” function. Taking the 3D body and projecting it onto a plane. Would have been fantastic if it would not generate three lines always on top of each other in general.

So, is there a function/workaround where only a sketch from a 3D Body with simple lines is generated? Or a function where sketches are checked for duplicate lines and possibly even cleaned up?

Thanks & Cheers!