So what do you need that space for? The option for the external GPU was a big factor for me. I can put two on this thing if I want. And still have ports enough to drive OP's three displays.
I think you can put 2 4K displays on each of the Thunderbolt ports, 2 4K displays on the two leftover USB 3.2 ports, and then 2 4K displays using the two HDMI ports, and that's without resorting to the external GPU.
You can host 2 M.2 devices and 1 SATA SSD so that's, what, 12TB SSD available? And still can resort to adding drives via USB, possibly via a hub which then gives you another half-dozen ports?
I feel like I can run my own space program with this thing.