Good topic 2019.
Two sons - I'm not sure the older one is a good example for today, because the time line is so different as I've explained in other threads.
For the younger one (2011 HS - and yes, the time line has changed even more since then), the only showcase he ever attended was one run by his travel team - NorCal Baseball. He did it after his sophomore year in HS and only because they asked all of their players to do so. He had a good HS sophomore season in a very competitive varsity program, but we knew his velocity was average at best. Something like 84. For a smallish (5-10) RHP, I didn't expect anything to come from it.
And nothing did.
The rest of the summer was playing on an excellent travel team that included 4 eventual 1st round draft picks (3 out of HS, 1 out of college). He/we just focused on getting better against great competition. 16U USA Baseball tournament in AZ and other highly competitive tournaments and vs. other good teams.
We did not send him to other showcases. Why not? I knew, that for someone to recruit him they would have to spend a little time to figure out why they should recruit him. It wasn't likely at all to happen from blowing 84/85 past good HS players in 2-3 innings at a showcase. He had an excellent HS coach and and excellent travel program and we thought they would do some of the legwork to explain why he was worth their time.
And they did.
Ultimately he was recruited by 5 or 6 schools. They were all schools that spent the time to figure him out. The PC for the school that he ended up choosing asked me early what showcases he would attend? I answered 'probably no more' and received a puzzled look back - but then I explained why and he seemed fine with it - and kept recruiting him. The next thing I knew that PC was showing up at his travel games during the summer.
I do believe our (my?) strategy was a good one in finding a group of schools that knew what they were getting and in the end they were all good choices and good fits. I do not think a showcase woulda helped him and may have in fact, hurt him.
He 'committed' to his eventual school early in his Junior HS season - but he/we told no one except his travel and HS coaches (and other coaches who had recruited him) and he had one of the two most successful and fun baseball seasons he ever had...all with a little secret held inside.
Hope that helps.