I dont have the direct answer for this question, but if the ETC is triggering your tyres pressures are still too high. On factory tyres I've run down as low as 12psi without drama on the super soft Stockton sand, on my previous 4WD a v6 Frontera with rims that are no doubt not the quality of LR, I used to run down to 10psi at Stockton, and could drive the beach in 2WD! 8O
As a sand guide though, I did the desert at 20psi, Stockton usually 15psi and Fraser at 20-25psi.
I do have the ability to disable the ETC in my MY00 Disco, but have never had the need to. If anything in conjunction with CDL it has helped, especially when driving through other peoples holes after being all crossed up.