Scenario off the top of my head: A shield that ships with a(n OLED) display.
Don't have to use it, but if you don't there'll be an ungainly hole in the stock plate. So the idea is to enable the display by default...but give users the ability to disable it.
A different plate could fit something other than an OLED...and there are footprints for resistors, so someone could pretty easily stick a different I2C device on there.
Problem:
The only way I know of to enable the display is to set CONFIG_ZMK_DISPLAY=y in the shield.conf file. But users cannot override this decision in their own repositories.
config ZMK_DISPLAY
default y
... doesn't have any effect in shield.defconfig. Neither does
menuconfig ZMK_DISPLAY
bool "Enable ZMK Display"
default y
Is there some other way to establish sane defaults that I've missed?