So I was tweaking the Details page...

... and decided to look a bit further into motorized linear potentiometers, The last time, in 2022, I merely just did a quick search and saw that the pot was long and priced at about £30. 

I did some searching on AliExpress and I found the RS60N11M9A0F and, subsequently, the RS60N11M9A0E.

These two linear sliders are 106.5mm long and, at most, 18mm wide. The 0F is slightly larger due to these black mounts:

One AliExpress review on a different listing used it for the Yamaha ProMix 01, a device from 1995:

The 0E is a tad more expensive, but still only like £110 for 10pcs:

ALPS, the manufacturer, had a 3D model downloadable on their site so I've been able to import it into Fusion 360 to compare.

While the 0E only has a touch-sense pin instead of a pressure sensor, nor is bluetooth enabled or LCD backlit, the dimensions between this and Tetrinsic are very close. If anything, it's just that small black plastic piece at the back that sticks out and makes the 0E longer, though I wouldn't be suprised if I have to increase the length of Tetrinsic resulting from the ball-chain being too slack when made IRL.

Each finger grip zone (yellow rectangle in image above) is about 8mm, so I could say that Tetrinsic has a stroke length of 55mm. The 0E has a 60mm stroke length. 

It's nice to know that I won't be completely solutionless if the BLDC motor I've got now doesn't work out for whatever reason. I'd just have to go to a brushed DC motor. The motor that ALPS uses is rated at up to 10V 0.8A, and there shouldn't be much of a reason why the BLDC and circuitry in Tetrinsic wouldn't be able to do the same, since I've been planning to use 9V at a current limit of 0.6A.

It's actually sounding like, as an input for a digital system, Tetrinsic could be somewhat of a high-tech alternative, considering the similarities in dimensions and compatible motor voltages.