I've read numerous accounts of the 265/65s a) rubbing at full articulation and b) requiring both the removal of the heat shield and requiring almost full deflation in order to stow them in the full-sized spare area. Also, I've heard a few people comment on the 65s getting in the way of the tow hitch. Given, many can solve the latter of those issues with a roof rack or swing mount but I have a seriously low garage entrance and I'm not ready to rip out the rear bumper just yet.
As for warranty, maybe it won't be an issue but, in my experience, the more work you do on the vehicle, the more that a dealership or LR can point to as something that had an ancillary effect on some other system that might fail. The loss of convenience and (minimal) risk is not work the extra 1"... at least, in my opinion. I'm sure I'll loosen up as time goes on but I'm happy playing it cautious for the moment.