If your staying at POR where there is multi bus stops do you go the first bus stop no matter where your room is? I ask as from what I know from years ago, they will only load ECV if there is no one on the bus. So that is why I ask, if we should just go to the first bus stop on the loop.
They will load ECV even if others are on the bus. They just ask for people to move. Also if they can not pick you up they will send another bus for you
Last time I was there, the "first stop" changed, depending on where the bus was coming from. We were the first, the third and the last stop at different times.
Usually the bus stop order changed for the buses that are Disney Springs and internal (just go around the resort). The Disney Springs buses act also as internal buses.
As the others mentioned, drivers will load ECVs and wheelchairs on the bus whether there are people on the bus or not. They may ask other guests to move or if the bus is too full, you might not be able to get on.
If you would be traveling to a park when a lot of other guests are returning to the resort, the bus might be full of guests returning from the park at the first few stops, so getting on at the first stop is not a guarantee of getting on all the time.