When increasing font size, the space on left of line # and between the debug column increases as well. This additional space does not seem to add any utility.
Not a hug issue, but for people who regularly use a large font, having that space grow feels like it add white space that is unused.
Have you had a chance to compare the layout in the latest release of Arduino IDE 2.x? It looks to me that this situation has been improved a bit. Here is the 2.0.0-beta.4 version you were using at font size 140: