You may well be aware that there is an external keyboard from Lenovo that mimics the Thinkpad keyboard: "ThinkPad TrackPoint Keyboard II"

Then there are mechanic keyboards with trackpoints from Tex in Taiwan: https://tex.com.tw/collections/all

I have a Tex Shinobi and the Lenovo trackpoint keyboard. The Tex is on my Linux workstation at the office.

When I had a Thinkpad and used the Trackpoint keyboard with my workstation, I had the same muscle memory for both. Bought a MacBook for battery life.

Yeah, easily $1k more if I could have that and perfect Linux support.