all different battlesystems always require their own summon method, you simply can't take any other way to summon and expect it to work in any battlesystem.
The problem is that the more complex battlesystems add their own data to the battlers. This usually happens as part of the battle-setup. an actor summoned after that setup is usually missing that additional data, and that is the cause for the crashes.
So to prevent the crashes any summoning plugin needs to know what data is added by the battlesystem plugin so that it can add that data to the new actor as well. And that means a working summoning plugin for in-battle-summoning needs to know and be written for the battlesystem.
You'll have to look for a summoning plugin that was either be written by Yanfly or written for Yanfly's system for the summoning to work without an error.
