Talk about the minimum length of the HDMI tracks on the board is untenable since the cable is much longer, here it may be a matter of their identical length, but it is not so critical. Yes, in the dimensions of your case, perhaps everything will not fit, I would just like to get a universal design that could work with both VGA and HDMI video output. Once again, I inform you that such a solution with parallel connection of two video outputs to Pico2 has already been tested and works fine. There is also a way to automatically detect the type of connected video interface when starting the program based on the state of the input ports.