Splitting up the sharedassets file

I notice that when I make a build from unity, the items in my Resources folder go into a sharedassets0.assets file.

To me that zero in the filename implies that I could have these assets split up into sharedassets0..1..2 etc.

Is that possible?

I know I could do this same thing with AssetBundles but that isn't an option for us, for some complicated reasons that I won't go into.

You can place items in your Resources folder into later sharedassets files in Edit -> Project Settings -> Player by changing the firstStreamedLevelWithResources value.

sharedassets0.assets contains all assets that are being referenced by the first scene in build (Build Settings → Scenes in Build).
sharedassets1.assets contains all assets that are being referenced by the second scene in build and weren’t referenced already in the previous scene.
And so forth.