He can do whatever, you can look at pictures of past builds, share with him to copy something, or get a version of it, or you can make a drawing yourself... Some people have specific requests for every detail, some just give him a general idea and let him run with it, any and everything in between!
No he is multitasking, not only is he emailing with many other customers for their own custom needs, he will be building many simultaneously, like the acrylics will be made together for example... So yeah customs get built along with some pre-built units that will go up on the next drop. Also he had to ship out all the customs and pre-builts from last time, so that takes up a lot of time instead of responding to the custom order emails yet...
However you may want to check your spam, I know someone's shipping email went there at least, but also you just need to be patient, maybe follow up in a week or two if you want, but yeah it can take several weeks so don't worry about that, just expect plenty of time and be chill about it? lol
I recommend skimming through this thread, good way to spend your time while you wait! Also we've recommended batteries in here like a page ago lol