Pat is old school but we love listening to his inputs
By the way, I might be doing the change at 5000 miles instead of 7500 based on the time it is taking me to get to that interval since the car was put in service back on Sep 7, 2018. And yes, I absolutely will be doing the oil analysis for every change on this engine.
To the OP, I had a '15 Mustang GT and used 7500 mile intervals for the changes, including the first one. If I believe the oil life monitor, it was telling me I still had about 20% or so of life left, meaning I could have gone almost to 10,000 miles. That engine was the Gen 2 Coyote 5.0L that used 8 qts of oil, which the Gen 3 version in the '18+ Mustang GTs and the modified one in the '19 Bullitt has 10 qts. I want to be darn sure I've got some data on the trade-off between more frequent oil changes and their impact on wear. I used my car as a daily driver with a 55/45 mix of city/highway driving, and no racing or severe duty conditions. I used the standard Motorcraft 5W-20 semi-synthetic and filter. After about 53,000 miles before I traded it in, the analysis showed that the metal concentrations were within normal specifications as measured by Blackstone Labs.
Oil is one of those subjects that elicits a lot of discussion and experiences to be shared. My opinion is that dumping those initial 10 qts after 1000 miles is too early. One of our members here went to 8000 miles on his car on the first change. I believe all of us are trying to do the best we can to minimize wear and tear on the engines of these wonderful cars, especially if we want to keep them "forever"!
Pat, you also had some thoughts on the impact of the PIDI fuel delivery system with regards to the Gen 3 5.0L and the maintenance. Feel free to share those here as well regarding oil changes.