Your point is certainly well taken, and you're 100% correct. I'm going to try to get myself onto different patterns and surfaces as much as possible between now and then, but, in the end, I'm going to have to make my best guesses because it's not easy to find sport patterns in my area. As such, I'm basing most of this off of what I've read/been told and the little that I've seen from USBC's streaming of various parts.
The BTU is a mystery. I use that ball at 500-grit all the time, even on our house shot, because the ball is way too squirty for me at any other surface. My hope is that I can use that ball to play straight. I've talked to some people who have already been there who claim that urethane is definitely an option early on in team. I have a Black Hammer (the new one), but I'd prefer not to throw true urethane due to the propensity for those balls to push some oil. The BTU should allow me a similar look. My worry there is that, for me, the BTU is very clean up front, and it still can come off the spot pretty hard. With that in mind, I'm worried that I'll get the ball down the lane, but it will jump too hard when it gets to the end of the pattern. Still, I know that I should be able to go pretty straight with it to start with.
The other balls are more predictable, so it's just a matter of surfaces. The Vivid is very smooth and rolly for me not matter what, so I definitely think I can use that to burn off some energy and tame down flying backends as needed. If/when I need to start creeping left, the Forza GT gets down the lane cleaner and offers more pop off the spot without getting crazy. The Byte will be cleaner still as a pearl, but that ball tends to produce more of a hook/set motion, which should be enhanced by the fact that I'll keep some surface on it. As stated above, I'm hoping that Tropical Heat Hybrid (Black/purple) will be good once the spot has opened up and you can throw it to the friction. That ball is clean up front and strong down the lane.
In the end, I'll make the best guesses I can just like everyone else does. It comes down to shot-making as much as anything anyhow, so all I can do is try to give myself a chance with reasonable ball choices and then see what happens from there.