I use a 23oz cue, 59 inch long. the main problem you might face,as others have said, increasing the weight from 18 to 20. Will have an impact on the balance. If you use it enough you can probably get over that.
I would try first increasing the weight little by little. You might find, you don't want it that heavy.
I got very lucky with mine, no weight bolts. Just a very heavy butt with a 3.90 oz shaft. the one thing that is different with mine, where the balance is, feels like it weighs 19oz, forward balanced.
At the end of the day, its what feels right for you.