The TBT4-UD5 is a Thunderbolt 4 docking station based on the Intel Goshen Ridge chipset. The display output capabilities of the TBT4-UD5 are ultimately determined by the display output capabilities of the host system.
Thunderbolt 4 host system:
When the TBT4-UD5 is connected to a computer with a Thunderbolt 4 port, the maximum number of displays that can be connected to the docking station is two.
*Note that base model M1 / M2 / M3 MacBook's can only support a single display.
The TBT4-UD5 has 2 built-in HDMI video output ports, and one downstream Thunderbolt port.
A USB-C cable or video adapter can be connected to the downstream Thunderbolt 4 port to connect a display.
The video outputs via the TBT4-UD5 are provided on a ‘first come, first served’ basis. This means that if a display is connected to the downstream Thunderbolt 4 port on the dock, you can connect one more display to one of the HDMI ports.
If both HDMI ports are occupied, the downstream Thunderbolt 4 port will not be able to output to a display. However it will still function as a Thunderbolt 4 port in other aspects.
Thunderbolt 3 host system:
Manufacturers have discretion when designing their Thunderbolt 3 systems in regard to how many displays are supported via a single Thunderbolt 3 port. Some Thunderbolt 3 systems support two displays, while other Thunderbolt 3 systems will only support one display.
The same ‘first come, first served’ process described previously within the ‘Thunderbolt 4 host system’ section will still apply if the host system supports two displays.
USB Type-C host system:
Host systems with only a USB Type-C port will be limited to a maximum of one display.