Deleting portions of a Line Renderer Line And / Or Combining Lines into one object

Hey all, I need some help solving a problem, I'm not sure how to approach it

I'm making a 2D game where the player can draw lines with their mouse to create shapes. The player needs to be able to draw a single shape using multiple strokes, or multiple lines. The player also needs to be able to delete parts of the line as if they were erasing it with the mouse. When the player is finished drawing the shape with their mouse, then the shape is 'marked' based on how close it is to some template shape.

I can draw lines with the Line renderer, but because the line is made up of an array of points, I can't seem to delete segments in the middle of the line. Also, if the user needs to make multiple strokes to create the shape, then I need to be able to combine all the lines somehow at the end for final marking, and to apply shaders to the shape as it's being drawn. This is difficult if the line is made up of multiple game objects.

I was thinking about having one master texture in the background that would work as a canvas, like a big square. If I could lay the lines over that canvas, and change the individual pixels on that canvas based on where I draw the lines to add and delete 'strokes', then I might be getting somewhere. Then I could just compare the canvas with the template for marking.

I can get an array of pixels from a texture with texture.getPixels(), but I'm not sure how to get the 2d array coordinates of a single pixel to change it based on the world position of a line that I'm drawing over the top of it with LineRenderer. Is there a way for me to combine a texture with a Line that I've drawn with LineRender? Do I Raycast individual pixels? from the camera maybe?

I'm scratching my head trying to think of a way to use Unity tools to create the system I have in mind. Any ideas would be appreciated!