Second confirmation of there only being 2 ACTIVE UFOs in the game:

void sub_8cb4f() {
if (((g_109e3)==0)&&((g_5f80)==0)) {
if (SCRIPT::_2C83A9DA6BFFC4F9(${ambient_ufos})==0) {
if (!ENTITY::IS_ENTITY_DEAD(PLAYER::PLAYER_PED_ID())) {
if ((g_17b95._f20df._ff0e)==1) {
if ((sub_8cbcd(PLAYER::PLAYER_PED_ID(), (l_3b), 1)<290.0)|| (sub_8cbcd(PLAYER::PLAYER_PED_ID(), (l_3e), 1)<290.0)) {
sub_8aeb2(${ambient_ufos}, 1424);
}
}
}
}
}
}

This code comes from the file main.ysc
Not quite sure what the global variables are, but what is for certain is that this is the code that activates the UFO's sounds files for Zancudo and Sandy Shores, the script itself(ambient_ufos.ysc) deals exclusively with sounds, so there being only 2 objects trigerring the script(Both are trigerred by proximity) means that no other UFO exists that has any sound effects.
Still possible that there are more silent ones, though unlikely, but either way this is a straight up confirmation that there are no active UFOs left to find.
There is one point of intrigue to me though, this script I just mentioned initializes the UFOs with these coordinates:
l_3b = {2402.87890625, 3777.0, 2490.0 };
l_3e = {1450.0780029296875, 3237.0, -2052.0 };
Yet the object loader I discussed earlier had its' coordinates set to
{793.05322265625, 5588.3857421875, 487.30999755859375 };
Now, of course that those coordinates should be different given they are to load the Chiliad UFO, but, 5588 shouldn't even be a legal altitude in the game world, given that the Sandy Shores UFO is placed at maximum altitude, isn't it?
Moreover, if both the "ufo" and "ufo_eye" models are loaded in this impossible position, how come there are no model loaders for the Zancudo and Sandy Shores UFOs? Something about these coordinates doesn't add up. I'm not quite sure what this means, if anything at all, but is anyone here aware of a way to translate these coordinates into a map position on the game world?