Code:
Hud.GetPlugin<ClickableChestGizmoPlugin>().Enabled = true;
Hud.GetPlugin<ClickableChestGizmoPlugin>().PaintOnlyWhenHarringtonWaistguardIsActive = false;
Hud.GetPlugin<ClickableChestGizmoPlugin>().Decorator.ToggleDecorators<MapShapeDecorator>(false);
Not exactly what you wanted but ... It marks all clickable "things", with cross. Just like when you put Harrington Belt on.
3rd line hides their locations on minimap.
You need to put it in PluginEnablerOrDisablerPlugin.cs file somewhere in
public void Customize() function