So this is SDK version 2019.06.19.20.14
Edit: Upgraded my project to SDK version 2019.06.25.21.13 and the bug is still present.
Final Edit: Alright I think I've figured out at this point what's going on. For some reason the SDK is uploading all the files of the unity project even if they're never used in a scene. I found this out when removing objects, probes, and materials from a scene wasn't decreasing the size, yet when I did some heavy texture compression it nearly cut the file size in half. It was uploading at about 425 MB and the compression made it about 250 MB.
Below is the original post. -------------------
I've been working on updates for my home world a lot and I recently removed some stuff from the map that wasn't needed and after I did this the world size went from ~180 MB to 307 MB despite my optimizations. I have a friend much more experienced in unity than I am and he doesn't even know what happened. I have future proofing disabled, which I know normally uploads all the files in a project. The weird part about that is even if it was enabled, I haven't added anything to the project that would cause it to double in size. The only things I did that might have possibly caused the issue is compressing meshes as well as changing the lightmapper method from enlighten to progressive. Besides that, removing objects should not have caused the file size to increase and in fact both the lightmapping method and compressing meshes should also lower file size. I've since reverted the meshes to what they were with no difference. (The models were only like 24kb anyway.) The other weird thing is in one of my previous updates I had used the progressive lightmapper and the file size remained about 180 MB.
If I narrow down any possible causes or find a work around, I'll edit my post.
Edit: Friend pointed out it might possibly be a light probe script being uploaded that I had recently downloaded and am not using anymore. Going to attempt to re-upload without it in the project. (Okay so this did nothing. Currently doing more troubleshooting.)
Another Edit: IT GOT BIGGER????? It's now 425 MB
Yet another edit: Uploading it with a new blueprint ID did nothing to help the size. Removing all light data only revealed that the world size was still much larger than it should've been.