Hi Jim Nocek
Thank you for posting in Microsoft Community.
You can use the Surface Dock Thunderbolt 4 to expand the number of USB ports on your Surface Studio 2+. The dock has three USB-A ports (one front-facing and two back-facing) and three USB-C ports (one front-facing and two back-facing). Congratulations on your new devices!
For optimal performance, you can connect your Surface Studio 2+ to the Surface Dock Thunderbolt 4 using the USB-C port located on the back of your Surface Studio 2+. Both devices support Thunderbolt 4, so this is the recommended method of connection.
You can connect your external devices to any of the USB-C or USB-A ports on the Surface Dock Thunderbolt 4. For faster data transfer speeds, it is recommended to connect your external hard drive to one of the USB-C ports.
As for the best ports to use on both devices, it is recommended to use the USB-C port on the Surface Studio 2+ and the USB-C port on the dock for the best performance.
I hope I have answered all your questions. Please let me know how it goes.
Kind regards,
Christopher.