How can i build my large world(not landscape)?deadline very near, please, help!

Hi.
i’m developing a game with my gamedev and we have a very nearest deadline. We must solve this problem:

We have 16 levels in our world, these are divided by interior scene and external scene.
I’ve a level called “SKY” where i can find my Directional light, my skylight nad my skydome. In the game i have a lot of static, stationary and movable light, no matter where i need.

I need to know how build only exterior with skylight and directional and interior without them.
if i make invisible the levels i must not build in a moment, when my build is finished and i must turn visible them and make invisible past build, i’ve the lights need to be rebuilt problem.

All the levels are under persistent, i can’t build all together because the 24GB max Build Override and my build crashes.
i’m using a swarm agent farm, so, the photons computing is shared to about 20 machines but about 10 are becoming available exporting nothing till the build ended. Why they are not working?

What is the right method to build this all and then export .exe correctly?

Hope someone can help me!!!
Thanks.

davide