Hi Bill -
Just FYI, the downloaded GB Library is stashed in "Library/Application Support/GarageBand"—it's around 14GB or so, so it's actually not too massive (as you saw, the Loops are stored separately, another 300MB). (At least I assume that's what you get from GB alone.. I had Logic installed before I installed GB—Logic uses the GB samples as well, in addition to its own (~70GB) of Library sounds (& loops), which does make a significant dent in a smaller startup disk, like, say, a 256GB SSD that comes with some of the smaller Macs).
In Logic, Apple is nice enough to include Sound Library Manager, which lets you install those individual packages (over & above the required 2GB of Essential Sounds) manually, selecting only the ones you want—I guess they felt that 14GB wasn't enough space to worry about, but 70GB was. Logic also now provides an option to lets you move its Library to another drive, added in response to years of user complaints about the 70GB install eating up too much space in the required install location on smaller startup drives.