I have 3 monitors connected to my computer. When OpenMPT's window is maximized, its recorded resolution is 1,936 pixels wide by 1,096 pixels high. Is there a way that I can make it utilize the full workspace (i.e., make it, in my case, 6,416 pixels wide [I have 2 monitors running at a resolution of 1,920 by 1,080 and 1 running at a resolution of 2,560 by 1,080.] by 1,096 pixels high) while it is maximized? With it having a recorded size of 6,400 pixels wide by 1,080 pixels high, it clearly does not take up the full workspace. When it has a recorded size of 6,414 pixels wide by 1,087 pixels high, I have missing information. Specifically: At 1,936 by 1,096, I see 36 rows (0-35) and 70 patterns (0-69) when viewing the Patterns tab. At 6,414 by 1,087, I see 35 rows and 256 patterns. Adding the additional 16 pixels to the height and width yields 1 additional row and 1 additional pattern, respectively. I looked at mptrack.ini. I modified the lines labeled ScreenCX and ScreenCY. But, that did not resize the window. Note: The recorded resolution of 1,936 pixels wide by 1,096 pixels high is for the maximized window. I have searched for tools to change the size of a maximized window, but to no avail.
I don't think that maximized windows can span several screens in Windows (you will have to keep the window in windowed state). If it is possible, there is no code in OpenMPT that should prevent you from maximizing the window over several screens.
You can just stretch it out even though maximize doesn't work.