Lousy trigger pulls have always been a major problem in bullpup designs.
The trigger is lousy due to the long, sloppy, and complicated linkage between the trigger and the sear.
Other than trying to remove some of the slack and sloppiness, there's not much that anyone can do.
Usually, attempts to improve the trigger result in trigger failures like failure to reset, or a trigger that allows doubles or even short bursts of full auto.
My suggestion is to just learn to shoot it as is.
You can spend money with a gunsmith, but this is unlikely to result in an improved trigger, and will most likely result in the above problems.
Sorry, but this is the down side to a bullpup design, and is why you don't see more of them.
