No issues with the WP rockets here. Or any of the smoke effects. Able to see them quite clearly and use them to find targets effectively.
They "work" but they work significantly less effectively than in reality. The main issue with WP rockets etc at present is that they simply emit a steady stream of smoke for a set time period somewhat like a screening smoke grenade, that is not what WP rockets/bombs/shells actually do.
WP warheads essentially explode spreading burning white phosphorus over a area (area size dependant on warhead type) all in one go. This produces a large smoke cloud very quickly, rather than a small billowing column. And on top of this WP also has a secondary incendiary function. And of course the smoke cloud should be affected by wind.
See video for a reasonable example.
http://youtu.be/JDc5NoQAD_A?t=54sIncidentally, training warheads such as those on the BDU-33 or M271 rocket has a similar effect, albeit a much smaller flash/smoke puff without the incendiary effects. Again there's no "smoke column for x seconds".