Hey Cocdawg,
All the same principals apply here as to your February "Help Me Out" thread. There are definitely no "must attend" events at your son's current age. He has early size and velo and you are playing in other events to where he will certainly not go overlooked. You are doing right by seeking out good qualified P instruction to keep him progressing and mechanically sound. Beyond that, align him with good competition that he enjoys, teams/teammates that he enjoys and let things play out for a while. If that showcase fits easily in the schedule and budget and his arm will be properly ramped up and he otherwise wants to attend, nothing wrong with playing in it. But don't feel the least bit of pressure that he needs to.
His size and velo now will likely start to get him put on some radar lists but will be meaningless in two years if he hasn't continued to progress and/or doesn't take care of his arm, and/or doesn't continue to develop a passion for the game. Too much pressure, too much push too early on is one of the many common factors that can result in lost passion for the game in the teens.