You are correct. It did happen here. I think that happened over a year ago plus.

this one I wrote about happened two weeks ago at the Miami MTI fun run. Heard water was rough and driver ran out of talent. Heard trim was set way to positive 38% and running to fast for conditions

38% is trimmed to the moon!!

What boat was it?

I do not have a modern OB, how much is 38%? What does that look like? I am assuming 0% is level?

0% is tucked all the way down. Neutral can vary per boat but probably around 20%.

These boats run with negative trim due to the lift provided. Runing positive trim, especially in rough, windy conditions is a recipe for disaster.

I believe you may be incorrect. At Lake X my trim was set to about 35 being neutral. It was previously at 10. The reasoning was for larger adjustment to be possible in both directions.

I think the 390 is set up similarly.

Greg is correct. MTI as well as myself and others set the Garmin displays and VV units with a calibration factor in the Mercury VV that can adjust the percentage amount to be what ever you like. MTI as well as Mercury Racing normally make 40% level with the bottom of the boat.
On my Skater if I add 2 degrees positive trim the reading is around 50%. Same I believe with the MTI's. Customers are normally told never to exceed 50%.
If you use the factory defaults on the VV I believe level is around 12% on a Garmin display.

I don't know who it was