Although the dock seemingly only has a single HDMI output, you can use one of the downstream Thunderbolt 4 ports to connect another monitor either directly through USB-C, or via an adapter.
and you’ll have to buy a $15 USB-C adapter cable to support a second. That’s cheaper than the alternative. The Kensington SD578OT is a solid Thunderbolt 4 dock in all respects. For those who ...