Changing 10.5 quarts is a flush, and beyond the scope of what was being compared. To me it's more like... I don't know, three quarts for an exchange vs. four for a dropped pan exchange. To me, the benefit of dropping the pan would be washing out the fines, not changing the filter. But some people feel strongly that the fines should stay in the system. Not my viewpoint.
I just dropped my pan and replaced the fluid filter. It is not a strainer, it is a gauze filter. I’ve had Toyotas before with a metal strainer and those only filter out big chunks. The filter in this transmission is more in line with what you would see in domestic transmissions.
Including the filter, my service drained out 3 quarts. There’s no way you were getting 3 quarts out without dropping the pan and the filter.
my van had 60,000 miles on it and the fluid was definitely due for a change.