That gives a somewhat more compact display with the default font for the main window (7 vs 8 pixels per column) and subwindows except for WINDOW_MONSTER (5 vs 6 pixels per column). That also can be closer to the appearance of the 1.4 interface which didn't round the width. MicroChasm's tiles still look okay though, with this change and the default font, they'll be scaled to 14 x 15 rather than 16 x 15 for display in the main window.
That gives a somewhat more compact display with the default font for the main window (7 vs 8 pixels per column) and subwindows except for WINDOW_MONSTER (5 vs 6 pixels per column). That also can be closer to the appearance of the 1.4 interface which didn't round the width. MicroChasm's tiles still look okay though, with this change and the default font, they'll be scaled to 14 x 15 rather than 16 x 15 for display in the main window.