Spawning chicken outside wall

So i made a throwable egg like item, since i'm making a mob based on chickens, and i have put to make it so the chicken summons when the egg hits a block, but the problem is if i use the egg on the floor the chicken spawns fine, but if i use it on any wall the chicken spawn stuck on the wall and dies.
I asked for help on the discord and at least the people that were online when i asked for help there not knew any solution, someone had suggested to use direction procedures but the "projectile hits block" not support the directions procedure.
I not want to make the chicken like mobs of my mod to be breedable so having the egg item to work is extremely important for me, so i need to know how i can spawn them without being stuck on blocks.