They should start loading at 9 am for a 10 am DHS open. Currently, they are only loading one family per cabin.
We stayed at Riviera and utilized the Skyliner to get to DHS on 9/15. They started loading at Riviera at 8:50 am and there was already quite a line at the CBR station when we arrived...
From the Home Resort Rules & Regulations:
The DHS bus stop is adjacent to the Skyliner Station. This option would require you to transfer to the Epcot line at CBR.
There is a bus stop at the CBR Skyliner Station which is one of the internal stops within the resort. The Aruba bus stop is close to the Riviera Skyliner Station.
To implement Google Pay in the mobile app would require they add a "button" (and associated processing code) similar to the one they added for Apple Pay.
At a physical payment terminal, Apple Pay & Google Pay both use NFC so nothing really needs to be done as long as they accept contactless...