Thank you for adding to the discussion!
I can see that you have also reached out to us directly via email@example.com with the same question. I have just sent my direct reply, however I wanted to add the salient points here for the benefit of anyone else following the discussion.
A MacBook Pro (14-inch, 2021) → https://support.apple.com/kb/SP854 or a MacBook Pro (16-inch, 2021) → https://support.apple.com/kb/SP858 with an Apple M1 Pro processor can support a maximum of two external displays.
Those model Macs have three Thunderbolt 4 ports and one HDMI video output port.
The external display support is based on ‘first come, first served’ model.
This means that even though those Mac models have four potential ways to connect an external display via the single HDMI video output port or the three Thunderbolt 4 ports, the Mac will only support two external displays when connecting an external display to the HDMI video output port or to the Thunderbolt 4 ports via a Thunderbolt 4, Thunderbolt 3, or USB Type-C device.
However, Plugable does offer a product based on DisplayLink USB video technology that allows you to circumvent your laptop’s total external display limitation in the form of the Plugable UD-6950PDZ docking station → https://plugable.com/products/ud-6950pdz
The UD-6950PDZ will connect to one of your Mac’s Thunderbolt 4 ports using the included three foot long USB Type-C cable (Thunderbolt 4 ports can also support USB Type-C devices).
The UD-6950PDZ will provide up to 60W of power to charge your laptop, as well as the ability to connect up to three 4K resolution displays (lower resolutions such as 1920x1080 are also supported) to the dock’s built-in DisplayPort or HDMI video outputs. Please note that the video cables themselves are not included.
The dock also provides six USB 3.0 ports (two on the front, four on the back) as well as a wired Ethernet network port and a single 3.5mm analog combination audio jack for use with speakers, headphones, or combination headsets.
One important note, you will need to install the dock’s required DisplayLink driver → https://plugable.com/pages/displaylink in order to use the dock.
Should you elect to move forward with a purchase of the UD-6950PDZ and find that the dock does not meet your needs, we do offer a 30-day no-hassle return policy for all products sold by Plugable and fulfilled by Amazon.