[VanillaRA] How to enable Aftermath units in Skirmish mode?

[Gerwin2k]

Regarding the Aftermath expansion units, such as the Mechanic, Shock trooper, Tesla Tank: These units work fine in the few Aftermath single player missions that have them. But I would like to enable them in Skirmish mode as well.

In "Redalert.ini" there is
[Expansions]
AftermathEnabled=yes
Which only seems to affect the display of the single player Aftermath missions.

Put:
[Aftermath]
NewUnitsEnabled=1
In "Aftermath.ini" and "Rules.ini", but that makes no difference.

Tried to override NewUnitsEnabled to 1 in cpp files in a custom build, but that made no difference either.

Also combined that with the selection of one of the Aftermath Mega maps. No luck.

Any suggestions on what to try next? Thanks.

[Gerwin2k]

Progress! This part of the code filters out the Aftermath units in Skirmish mode.
These units appear when this section is commented out
So somehow NewUnitsEnabled was still set (back) to 0 at this point...

house.cpp line 835

    /*
    ** If this is a CounterStrike II-only unit, and we're playing a multiplayer
    ** game in 'downshifted' mode against CounterStrike or Red Alert, then
    ** don't allow building this unit.
    */
    if (!NewUnitsEnabled) {
        switch (type->What_Am_I()) {
        case RTTI_INFANTRYTYPE:
            if (((InfantryTypeClass*)type)->ID >= INFANTRY_RA_COUNT)
                return (false);
            break;
        case RTTI_UNITTYPE:
            if (((UnitTypeClass*)type)->ID >= UNIT_RA_COUNT)
                return (false);
            break;
        case RTTI_VESSELTYPE:
            if (((VesselTypeClass*)type)->ID >= VESSEL_RA_COUNT)
                return (false);
            break;
        default:
            break;
        }
    }

[Gerwin2k]

My testing shows that this bit of code prevents NewUnitsEnabled to remain at 1.
scenario.cpp, line 2636:

#ifdef FIXIT_CSII //	checked - ajw 9/28/98 - Added runtime check.
    if (Is_Aftermath_Installed()) {
        if (Session.Type == GAME_SKIRMISH || Session.Type == GAME_GLYPHX_MULTIPLAYER) {
            bAftermathMultiplayer = NewUnitsEnabled = OverrideNewUnitsEnabled;
        }
    }
#endif

In globals.cpp there is this:
OverrideNewUnitsEnabled = false; // ST - 12/13/2019 12:21PM
and it seems only the remaster dllinterface.cpp has the code to make it become "true". While the non-remaster build has no such means. Non-remaster builds should not use "OverrideNewUnitsEnabled" there, in scenario.cpp.

[Gerwin2k]

Continued as an issue here:
#926