If you did 12.77 on 88", then you'll certainly go faster with a larger gear. I'm fairly certain that you'll be 12.0X with a 14 cog the first time you try it.
I'm not too familiar with the UpUpUp power gear as I've never used that as a training tool. If you have a kickr, then you can do some experimentation using cadence and speed plots to dial in your "power gear".
Gearing is incredibly personal, so I hesitate to follow a "cookie cutter" program for training when it comes to gearing. Some people can develop speed easily at higher RPM ranges. Others need to gear up and torque their way to max speed. If your kickr can plot power and speed, you can use those curves to see where your sweet spot lies in the RPM range.