I'd wait.
The Police trigger/sear spring is a little heavier, and that's to help prevent an accidental discharge when under stress.
This is NOT a case of being REALLY heavy, it's just a slightly higher pull. Certainly nothing most people even notice.
A shotgun is different than a pistol or rifle, and the trigger pull is not as big a factor.
In reality, you'll likely notice very little difference, and the slightly heavier pull may actually be a benefit.
Remember, this isn't a sporting rifle where a light trigger is an aid to accurate shooting.
The slightly heavier pull isn't a real factor in a defense shotgun, and it is an added safety feature you won't notice unless you compare it to a sporting 870.
The trigger/sear spring is easy to change:
Remove the trigger plate from the gun.
Uncock the hammer. Put the safety OFF.
At the rear of the trigger plate is a large diameter bushing through which the rear trigger plate pin passes.
It has a "D" shaped retention spring in it.
Simply push that bushing out.
This will allow the trigger to move forward slightly, taking the tension off the trigger/sear spring.
Pull the spring off the trigger and sear lobes, and insert a different spring.
Reassemble in the reverse.
One bit of advise:
Remington advises disassembling new Police guns and spraying dripping wet, inside and out, with something like Rem-Oil or CLP Breakfree.
This is to dissolve and wash off the coating of cosmoline they spray Police guns with.
The cosmoline is ONLY for storage and shipping, and if it isn't removed, the gun can rust.
Disassemble per the owner's manual, including the magazine.
Spray everything dripping wet and allow to soak for 30 minutes.
Wipe off and reassemble.
I used CLP Breakfree, and this "soaks" into the rough parkerized finish and does a great job of both removing the cosmoline and impregnating the metal with a rust proof coating.
Is the spring easy enough to change?