This one kind of explains itself -- when you open Window Settings you can click the increment (see image) to toggle between 1 and 5. When you choose 5 it puts five-pixel notches in the slidebars, like a snap setting.
I've had this in my game forever and always keep it set to 5. It's saved a lot of fidgeting with transparency values, but then y'all already know I'm obsessive about such things. There was a technical flaw with how the values were displayed so it never got published, but over the holidays I got that all ironed out. Check for updates to get it. As always: Thank you, Patrons!