I think the FAL has a fair uphill battle for target trigger work. I went through this on a L1A1 lower that was Century buttholed and they come with a special century GMC coil spring for a trigger return spring. It's way too long for a corrected lower and only fits the long bored hole in the buttholes.
I got a few pieces of possible likely sized spring from my gunsmith friend and tried to make them work. On the test bench I had nice smooth light to medium triggers. On the range they lacked power or speed to insure a trigger reset. I ordered a replacement L1A1 trigger spring and although the trigger was a bit heavy it worked well and was dead nutz reliable. Shocking right? Fortunately the hammer and sear I got were smooth and square and were creep free. You can have a good trigger that is relatively heavy as long as it is creep free. In fact I'd rather have heavy and smooth over light with some crunchy stop over hangups.
A firm spring in a trigger job is a good and reliable thing. That's one of the biggest issue with guys messing around with the Remington M700 triggers. They work fine if they're left in the 3.5 pound and higher range short of severe varnishing. They get funky when they're set lighter than they were designed for, add in some varnish and you will find problems. Add in the remington trigger pack springs are sitting in threaded holes. I wonder how much better the triggers would have been if that section of the trigger packss were smooth walled. My smith pointed out that little fact and he thought it was relevant in the lightest settings in the Remingtons.
Anyways i digress, but I agree, it's meant to have a bit of weight behind the trigger, the guys were running, bouncing around in boats and armored vehicles, out of helos. That job demands a firm trigger.