As you probably know, the Edge-V has other display output options. “Edge can support dual independent display over USB-C, HDMI, eDP or MIPI” Finding a larger display, appropriate cable(s) and touchscreen that would work on those, would require a lot of homework. USB-C DP may be easier, as I have seen some displays that use a single USB-C cable for display and touch. However, those probably require drivers that may or may not be available in firmware for Linux or Android.
Several users have the Edge-V with the Khadas 5" display/touchscreen, reading those threads should give you an idea about using those ports(DSI, Touch, and E-DP). May want to disregard comments related to display’s size and look more for user experience-related comments.
I would be interested to learn when you find a solution, please keep us posted.