Ran installation first time to create answer file (attached).
If not on Oracle VPN, installing with answer file in silent mode works fine. If on Oracle VPN, the equivalent installer command seems to lay down most (all?) of the bits, but hangs and consumes a lot of CPU. Unknown if this occurs on other platforms.
Command to run installer with answer file:
./ogs*sh -v -s -a answerfile
Attaching the output of verbose logging (typescript).