I've bought my fair share of docks and peripherals over the years as I love multi-monitor work set ups. My main workstation comprised a client issued HP corporate laptop that I used with a couple of older Dell U3014 30" displays. This was nice, but I was itching to add a third display that I had lying around and found an adapter that works perfectly.
It's a 'Selore' branded USB C to Dual HDMI Adapter,7 in 1 USB C Docking Station to Dual HDMI Displayport VGA Adapter,USB C to 3USB 2.0, Multi Monitor Adapter. I'm sure there are plenty of versions and brands of this, but this one does the job.
It's got 2x HDMI outputs and a Display Port. I connected up my 3x 30" panels, et volia!
Unfortunately, this only works its magic with Windows as it seems to be able to mirror on Macs, but not span. For now, though, I'm happy with it and can multitask happily.