The plan was to plug a DAC and the USB powered speakers I bought into two USB ports on my monitor. That way I could use the speakers on both my MacBook Pro and my work laptop. It didn’t work. The DAC and the speakers had power, I could switch them both on, but the MacBook Pro couldn’t find them. It wasn’t an option in my sound preferences. I moved the DAC to my final USB-C port on the MacBook itself (via an adapter) and it worked fine. I listened to a little King Crimson to test drive (Epitaph) and it sounded 10 times better than the speakers built into the monitor. I doubt I’d use them to mix a song or anything, but they sound great for watching Netflix (I test drove it with an episode of Community. The one where Jeff takes a pool class and they meet an Abed look alike).
So it didn’t work the way I planned, but I wasn’t really intending to use the speakers with the work machine anyway. It would have been nice to have the option, but I don’t really need it. It worked well enough on the Mac though, and that’s the important part. So we’ll say it’s only a partial fail.