Is partial draining/refilling a big hassle for you?
If not, you might experiment with bumping your CYA up to see if you can hold on to your chlorine, and if it doesn't work any better, drain and refill as needed to get it back down if you want.
If not, you might experiment with bumping your CYA up to see if you can hold on to your chlorine, and if it doesn't work any better, drain and refill as needed to get it back down if you want.