My question is, can I run another node on my other Apollo? Would it work since they're both behind the same firewall? Can you have multiple nodes behind a single firewall without having multiple public IP addresses?
Yes, you can 2 or more as long as you manually open unused / uncommon ports and map it to additional Apollo.
But not very useful. You have great info about this from jstefanop and psycodad a few post above. Please read.
Dont waste another 64GB drive. Is not useful. For Apollo batch 1 owners YOU ONLY NEED TO UPGRADE ONE APOLLO. OK?
One node by IP. Only consider to have two nodes if they use different IP. One at home and another at workplace is rigth, very useful.