When do you stop cubing for boss %?

A lot of it really depends on what you do/what you plan to do. You can get by with a lot less % Ignore if you don't ever plan on doing things like CPB, CRA, etc.
There's also % Att to keep in mind as well.

Forgot about % att. My goal is those bosses i'm just trying to figure out what to keep or not to keep when i'm cubing most of the time.

Still have sw 30% gollux 20% tamer 20% to still add on to my boss total.

So that should be a huge boost when the time comes.