I tried configSourceModList but it's not returning results as described in the Wiki.

Wiki's example gives:

_mods = configSourceModList (configFile >> "CfgVehicles" >> "Man");
hint str _mods; // ["A3","curator","heli"]

But when I try it I get

_mods = configSourceModList (configFile >> "CfgVehicles" >> "Man");
hint str _mods; // ["curator","heli"]

So I can't see if something was originally "A3". (Unless I'm misinterpreting it)

To give another example:

diag_log format ["%1 - %2",_item, configSourceModList (configFile / "cfgweapons" / _item)];

"launch_O_Titan_F - []"

"launch_O_Titan_ghex_F - ["expansion"]"

If we make a little mod to change the names like this:

class launch_O_Titan_F : launch_Titan_base {
    displayName = "Titan A3";
};


class launch_O_Titan_ghex_F : launch_O_Titan_F {
    displayName = "Titan Apex";
};

Then it returns:

"launch_O_Titan_F" - ["@myMod"]

"launch_O_Titan_ghex_F" - ["expansion","@myMod"]

So you have no idea that "launch_O_Titan_F" is a Vanilla weapon as the mod array only contains the mod name that overwrote the config and not any indication that it's originally "A3".