They are controlled via an electronic selonoid which controls oil flow. This is how many cars control their variable valve train - which I do have experience with.
These valves are usually full on or off at rest. So I’d guess they will be full soft. Those valves are either on/off style or PWM control. On/off would be in appropriate so you can bet they are PWM. IF you get those, I’d suggest getting a simple PWM controller with a manual knob for testing them. You might find that is suitable (just being able to dial them to a setting), or you may want something more elaborate that firms them with speed and/or under braking.
For testing, I’d suggest something like:
EBay Search: DC 10-55V MAX 60A PWM Motor Speed Controller CW CCW Reversible 12V 24V 36V
But you can do something much smaller for permanent use.
That goes WAY over my head I'm afraid. Wat is PMW?
I would like to keep the bike simple. It would be great to have adjustable shocks, but I really don't need anything as sophisticated as being able to adjust on the go. I'd rather go with something that I can set up (with a spanner/screwdriver) for normal town/A-road riding and then leave it like that until I'll be tackling the Nurburgring (which ain't gonna happen soon or regularly!)
I think I'll pass on those and see if I can find some that are manually adjustable... just a matter of looking for stuff off older bikes.