I have the same late model A/C unit as is available from RN now. The ones with the controls on the drivers side.
I have gone through a complete journey of exploration with that A/C, working directly with the UK factory that makes it for LR.
I ended up having to replace the A/C internal wiring harness to get everything to work right, but after all was said and done, all 3 settings were still warmer than I would have expected. Included under warranty replacement with the wiring internal was a new probe. I ended up disconnecting the original installed probe that sits somewhere around the evaporator. I'm not sure it disloged and fell closer to the evap or what. I put the new probe closer to the outlets.
What the probe does is feed the ecu with the air temp. the closer it is to the evap, the sooner it hits temp and triggers the ECU to turn the compressor clutch off. I was finding that even though my outlet temp was relatively warm, the ecu was disengaging the clutch too soon.
with the new position of the probe, my three settings are perfectly chilly in a nice graduated increment. You may either be suffering from a slipped or faulty probe if your a/c is too warm on all three settings, but you do need to make sure you have sufficient refrigerant charge first.