Could Doom Retro have ENDOOM support? Something like the following CVAR
r_endoom: controls how ENDOOMs are displayed. Accepts the values
off: don't display ENDOOM screens (the current default)
pwad: only display the ENDOOM screen from the current PWAD
iwad: only display the ENDOOM screen from the current IWAD
all: display ENDOOM screen from the current PWAD if present, then display the screen from the IWAD
So if someone were to quit, for example, REKKR: Sunken Land while having r_endoom set to pwad they would see it's ENDOOM screen before quitting.

Could Doom Retro have ENDOOM support? Something like the following CVAR
r_endoom: controls how ENDOOMs are displayed. Accepts the valuesoff: don't display ENDOOM screens (the current default)pwad: only display the ENDOOM screen from the current PWADiwad: only display the ENDOOM screen from the current IWADall: display ENDOOM screen from the current PWAD if present, then display the screen from the IWADSo if someone were to quit, for example, REKKR: Sunken Land while having
r_endoomset topwadthey would see it's ENDOOM screen before quitting.