You have to choose whether you want to shoot at full or half power and zero the sights to that.
There is no way around the basic physics.
The HW45 is the most accurate spring pistol I've shot, but it takes weeks and weeks of practice to get there.
Concentrate on the style of hold, they shoot best with a very light grip - use the 1911 combat hold but don't wrap the thumbs around the gripframe.
Weirdly, the design of the grip on the "star" variants basically forces the shooter to adopt a grip style that doesn't work very well.