09A Overfilled?

A friend of mine recently picked up a 250k mile '05 Jetta BEW with an 09A. It has the classic 09A random no reverse issue. The car drives great in all 5 forward gears; however if you drive the car long enough for the trans to warm up it just pukes transmission fluid. We decided to drain the fluid and replace the pan gasket before tackling the solenoids. When we drained the transmission fluid we drained almost 3 gallons of fluid! Everything we've read says there should have only been 3-4 liters/quarts of fluid with a max system capacity of 7 liters. This would explain why fluid was just pouring out of the breather with enough velocity to blow the breather cap off, but where did this much fluid come from?!

Is it possible the torque converter has a bad seal? Maybe the previous owner thought the lack of reverse was due to a low fluid level and just kept adding fluid hoping it would fix reverse? Maybe we found a car that magically produces transmission fluid?

now when you have the correct level does it drive better? 3 gal, unbelievable, should be like 3.2 qt or so, or even less like 2.75 qt when you use the check level plug

Dry fill of the Jatco 09A is listed as 7 liters. But just a drain and fill through the bottom only gets about 2.5 or so. Taking the valve body out maybe gets about 4.5 out.

Final verdict was 9-10qts of ATF drained. Fluid all looked pretty fresh for a car with 250,000 miles. Someone likely added new fluid without draining the old fluid, or just way overfilled the fluid.

We added 3.8qts of new Valvoline ATF and it drove like a top through all 5 forward gears. Shifts were so much better and less aggressive. Unfortunately still no reverse, the solenoid is likely shot. That's a project for another day; we're just happy we resolved the fluid leak!