I don't have recent experience, but in 2019 and early 2020 we had 100% success. For balls that are in high demand here is what we did

1) Sign up as noted by DeepCut and entered our credit card
2) Used the time app on an iPhone showing tenths of a second and ticking each second
3) Be on the map at 7:00am and select a ball immediately.

We had a mobile wifi hotspot supplied by Cello Mobile (no affiliation) and used an iPad from the boat - irrelevant perhaps.

On our 2021 trip we didn't need to use BoatyBall