I'm having difficulty trying to work out which sensor you're going on about.
You say you're building a 130, I presume that's a Defender. If that's the case, then I didn't think that the Defender was ever fitted with ACE, but I'm sure somebody will say if I'm wrong.
If it is ACE or Active Cornering Enhancement you are talking about then you don't just "switch off that sensor", it's working all the time. The basic way it works is that there are two accelerometers, one high up in the roof and the other down low in the vehicle. When the vehicle is cornering, centrifugal forces tend to make the vehicle lean outwards from the corner, "body roll". To counteract this roll the ACE ECU will detect the difference between the two accelerometers and allow the hydraulic anti-roll bars to inflate or deflate as is appropriate to force the vehicle to ride flat through a corner.
So, if you haven't got hydraulic active anti-roll bars and an ACE electronic control unit, then you don't need the accelerometers.
If however you're talking about the HDC or Hill Descent Control system, then this is an automatic braking system which is driver selected, that is it has a switch on the dashboard to enable it. It works as a part of the ABS (Anti-lock Braking System) and is used to descend very steep usually off-road hills. When switched on, it allows the vehicle to drive down the hill, automatically applying the brakes to the wheels individually to prevent them skidding whilst maintaining a suitable slow speed without the driver taking any other action that steering. The driver then switches it off again when safe level ground is reached.
As has already been said, these are totally separate systems.
A part number for the "ECU kit" might help us.