Look......right now your game is whatever it is.....good, bad, indifferent.....doesn't matter.
You have to concentrate on the game played between the ears.
Don't change anything equipment wise before a tournament......play with what got ya here.
Only change something if it's broken, or your sure it's not performing. It doesn't sound like that in your thread. What you know and can count on is what you have right now. What you don't know is what you'll wind up with until you get there and it will be different.......maybe better but probably not for awhile with the way new tips perform even after careful shaping.
Tips have to play a bit in order to assume a reliable trustworthy shape, hardness, and your sense of what seems to work best with your vertical and horizontal English application. That takes a little bit of time which varies with the brand & hardness of the tip, as well as the player's learning curve. Buddy, you don't have that luxury right now and so unless you don't trust your tip, and if that was the case you'd know it, stick with what ya got 'til after the tournament.
I also play with Kamui Black medium tips on my cues and it's a hard tip that generally has a long life to it unless the tip has been aggressively sanded or reshaped during its life. It doesn't sound like that to me from thread but I'm presupposing because you have the cue and I can't see the tip. Why don't you post photos of the tip and I'm sure you'll get feedback, mixed of course I'm sure, but it may make you feel better about it. I think you will be okay but let's see what the tip looks like. Post a photo of the top of the tip and also include a photo of the side of the tip with part of the ferrule included so the height (remainder) of the tip can be assessed. That's more important than a top down photo of the cue tip.
Matt B.