Yes, the dipstick port has a plastic plug on the right side of the transmission, higher up on a ledge. The check plug on RWD 6L45 is facing the back, just above the pan.
The dipstick hole plug is like a close-ended tube with a loose plug in it. I think the plug expands the tube to seal. On first removal it might be a little difficult, but subsequently I can easily remove it with 2 fingers. Lifting up the plug, and then push up farther. The first time I believe I used a long screwdriver to push up on the plug. The access in that area is a little tight but doable.
The ATF cooler lines are on the left side of the transmission, and on my 07 the pipes/hoses go forward to the lower driver side of the radiator. There's a cooler there. I did not want to mess with that connection.
Here is an aftermarket dipstick picture. Clean the area, mine had lots of road dust accumulated around it.
