I used the code in the GitHub PR:
```
["loadout", {
diag_log text format ["TEST %1 loadout EH [%2] %3", diag_frameNo, hmd player];
}, true] call CBA_fnc_addPlayerEventHandler;
player addEventHandler ["SlotItemChanged", {
diag_log text format ["TEST %1 SlotItemChanged EH [%2] %3", diag_frameNo, hmd player, _this];
}];
```
Ran a mission, dragged night vision goggles around, used `linkItem` command.
The code below was used for the editor tests:
```
_unit = (get3DENSelected "object") param [0, objNull];
_unit addEventHandler ["SlotItemChanged", {
diag_log text format ["TEST %1 SlotItemChanged EH [%2] %3", diag_frameNo, hmd (_this select 0), _this];
systemChat format ["TEST %1 SlotItemChanged EH [%2] %3", diag_frameNo, hmd (_this select 0), _this];
}];
```