Toyota LandCruiser: black smoke on acceleration

It’s not normal to get black smoke under acceleration, that suggest it’s being over-fuelled and should be looked into. Aftermarket chips can be worthwhile, but they generally take the engine closer to the limit than does the factory chip, so you need to find an installer who can be trusted to do the job well. I wouldn’t do it on your car until the warranty runs out, and then consider it.