The Gen3-LMS determines the weight of the lifted load by measuring the pressure in the lift cylinder. When at the minimum boom angle stop, the boom is resting on the chassis and is no longer supported by the lift cylinder. As there is 0 pressure in the lift cylinder the Gen3 load reading is also 0.

This can also be observed in machine's with stabilisers. When the stabilisers are fully lowered the front of the machine is raised by a few degrees. This may allow for the boom to reach the minimum boom angle stop and still have the attachment off the ground and allow the boom to extend. However the load reading on the Gen3 will remain at 0 matching the pressure in the lift cylinder. However the machine's inbuilt LMI will still function and provide a cutout when required.

In the above scenario the machine's inbuilt LMI will still function. This is because the LMI uses the force on the rear axle to measure the lifted load instead of the pressure in the lift cylinder. Therefore it's operation is not affected when the boom is sitting on the minimum boom angle stop. Please read Differences Between LMI and RCL for a better understanding.