The pre -13 TRG trigger is adjustable below ca 2 lbs, but doing so not knowing what you are doing might lead to its destruction.
Send to Beretta to repair/replace.
Post -13 triggers can't be abused in this way and might be a bit inferior in feel.
So, if trigger weight is your reason, go for what ever trigger you want. But I dare you to find a trigger with 2 lbs pull weight that is better than the TRG's.