The Adventist GRI was indeed more upfront about YEC problems in the past, and provided some good information for me in my journey away from YEC. They discussed things like palaeomagnetism, the Oklo phenomenon, early geologists being unable to find evidence for their YEC beliefs, and were able to say in 1981 "At present there are no data that independently suggest either 6 day creation or placement of such an event in the last 8000 years." They then listed about a dozen indicators of an old Earth.
With the current ultra-conservative leadership of the Adventist church, they will be more mainstream YEC these days.