The key to using the LEM trigger with precision is the same key to using any DA trigger with precision: A good, rolling break. Prior to using the P30 I thought I knew what a rolling break was, but it's only after having used one for a while that I've come to really understand what a good rolling break actually is....and when I can manage to not screw up the sighting bit I can shoot with some pretty spectacular accuracy. The LEM trigger may offer some benefit in that it's typically lighter and smoother than the DA trigger pull of a DA/SA configured pistol, which would make it easier to have that good rolling break...but by really focusing on applying consistent pressure and constant motion of the trigger when shooting in DA mode you should be able to get excellent results even with the DA trigger on your current P30.
The key to shooting DA "fast" is to do all the same things...only quicker. I can go reasonably "fast" and make hits if I just take that extra bit of "time" (in reality only fractions of a second) to press all the way through the break consistently rather than just hammering the trigger to the rear in one violent motion.