I have just purchased Scapple for Windows. My laptop has a 4k screen and the head of the arrow between notes is so tiny it is almost not there. I have attached a screenshot. If you look closely, you can see it is there, but it is barely more than a dot. The ability to change the formatting of the line ends would at least allow me to make the ends larger. While we’re at it, it would be nice to be able to change things like line thickness and color as well.
You may have some luck with the latest high-DPI trick I listed at [url]https://forum.literatureandlatte.com/t/scapple-high-dpi-support/31250/5] .