Probably those will improve things, but I'm not sure how much.
The heaviest 870 trigger here is about 5 lbs, and none are so bad that slug groups are compromised. In fact, my Model 94 is worse and still shoots well.
I've had Timneys on some bolt guns. They do give a very nice feel,light,clean and crisp.
Another possible tweak for your breacher is adding a trigger shoe. The greater surface area mimics a lighter pull. Most people using them also think they give a better feel of the break point.