I have one thing to suggest: when we have had ADR's at other resorts, we have had a lot of luck each time letting our bus driver know we that we had ADR's at the resort and just asking what's the best way to get there. For example:
Staying at Pop, we had dinner reservations for Boma around 5:30. We left Pop at 4 PM to catch a bus to Animal Kingdom. That time, the bus driver actually asked if anyone had dining reservations at AKL and we said yes. There was only about 10 people on the bus. He dropped our family off at AKL and we had a bunch of extra time to explore the resort and the main reservation before our ADR. It was very convenient.
During a trip years later, we were again staying at Pop we had a reservation to the signature restaurant at AKL. We hopped a bus to Animal Kingdom and let the bus driver know that we had ADR at AKL and we were able to get dropped off right there again. It was great.
Staying at AoA before the Skyliner, we had dinner ADR for Cape May Cafe. We hopped a bus to DHS and planned to take the friendship boats to Beach Club. There was a storm that popped up and we were afraid the boats would not be running. We told the bus driver we had ADR at Cape May and he dropped us off right at Beach Club. Worked out very well. We have always found that the Disney Transportation folks go out of their way to help out.
On the flip side, we almost always have our car with us and have had lots of luck driving to resorts, even without an ADR. We have done this probably have a dozen times. I just drive to the gate of the resort we want to visit. We tell the guard where we are staying and that we would like to visit the resort for a couple of hours to grab a bit to eat, do some shopping and scope it out as a possible future place we may stay. We have never been turned away using this approach, although once or twice we have been told that it's a 3 hour max.
Good luck!