Current possibilities are too limited, there should be a new select / dropdown setting type.
For example to select which submode, Starting Weapon and so on.
A text cannot fit that purpose as the player can type too much bad things.
values would be strings so the default one would be a string
Could work like that :
my_select = { label = "SubMode", type = "select", description = "", options = {"Survival", "GunGame", "Sharpshooter"}, default = "Survival"}