Try using softer shot?
Swapped back to shot straight on the line two years ago after trying doubling the line to put the shot on and using Steve Mayo’s adaptors.
Not had a single breakage in that time, despite having many tons and fish averaging 5-7lb each with odd ones well over 10lb.
I use Anchor Double Cut shot and 6lb Ultima Power Plus mainline.
Certainly get more bites using a unloaded float on hard fished waters, in my opinion. They pop up much faster, keeping the float and bait right in front of the fish at that crucial moment when you are likely to get a bite.