Doesn't matter really, they are just springs that cab be replaced for very minimal cost. I personally do not believe in manipulating the springs as that can cause damage if not done properly. However, I do not believe that is the case with the triggers I linked to above. That would not be very good since there would be inconsistencies between each trigger as Bill does custom jobs manually.
These triggers appear to be more along the lines of specially designed springs for the trigger assembly.
Of course this is my opinion and is not based on fact but more on business sense.

