Create an endless wave?

Hi all,

I'm loving poolboss and coregamekit, it''s all working very well atm. I'm currently at a point where I need to create an endless (literally) wave, so that once a single enemy in that wave is destroyed, I create a new (stronger) one spawning at start point again. What's the best way to achieve this? Is it to handle the destruction of a killable then spawn another object in the pool immediatley or is there a way to do this without script that I'm missing?

Thanks in advance