Strikto I have a question about CustomEntity, specifically regarding ArmorStands created during the initialization of this object. Is there a way to hide them from players in spectator mode or at lest get that specific armor stand beacuse my plugin won't detect it somehow.
Verum I do not believe there is a way to hide the invisible armour stands from players in spectator as this is vanilla behaviour. As for your plugin detecting it, I can only recommend you check the API to see if there is way or open a feature request on the GitHub to see if they will add it.