The Range Rover does't lower itself 1.5". It's more like 10mm.
20mm is probably enough to throw it out of alignment. It's up to you if the drawbacks are worth the benefit of looking better.
You’re right, it’s .8”. Which is about 20mm coincidentally. Anyway, I had 4 old range rovers and 3 LR series, and have done 1 alignment, the first LR3 which came misaligned from the factory. So I’m not super worried about it. However I’m willing to concede that standard height is “best”.