Is there a way to show the intersection of the centre lines in a pattern by bolding or highlighting the horizontal and vertical centre in some way? I know there are the red arrows that point, but with larger patterns that's not helpful.
We're all mad here....You may have noticed I'm not all there myself. - Cheshire Cat
There is nothing in the program at this point that will do that. Remember that the center "line" is not always a line but a row/column of actual stitching.
What you can do is what I have done mainly for print purposes. I have done this for design purposes also. Chose a color that is not in the actual pattern - a definite contrasting color is best. Manually create a LOOOOOOONG horizontal and vertical line as close as possible to the center. It will be a half-stitch off if the rows and/or columns are an odd number. When you are completed, rather than delete the lines manually, you can just eliminate the color entirely and that will remove the lines.