Is it okay if my kimchi has large air pockets?

Yes, you have to get rid of those air bubbles to ensure even fermentation.
Cutting them smaller (even into bite-sized pieces if necessary) seems like a good idea to me.

Just like Sanne said, yes you should get rid of empty spaces between the quarters or it must be spoiled soon.
I also make kimchi with savoy cabbage (chou frisé in french). Its firmer texture makes it last longer than nappa cabbage and its stronger taste makes it perfect for fried rice (chopped finely and panned with butter !!).
A key for the next time you use savoy cabbage : you can make pouches with the great leaves, fill it with the smaller and cut leaves.
The cabbage is pressed inside the pouches and the pouches are pressed into the jar : no air.
Bye and happy kimchi to you

Normal small air bubbles and larger bubbles that occur throughout the fermentation process have no impact on how well the kimchi ferments. There is no need to release the trapped gas as long as the kimchi is mostly submerged in the liquid.

No problem at all – it’s common for homemade kimchi to have air pockets and it doesn’t make it any less delicious! Just give it a good ol’ taste test to make sure it’s still on point.