We have reviewed internally and can relay the following:
Regarding PT1 not sending a full chain, this is an oversight on our part we will correct in the near future with a separate PT1 deployment, likely early next year.
For production certificates, I can confirm we send the full chain. You can see this running SSL Labs against one of our production-staging endpoints in Akamai. URL: https://www.ssllabs.com/ssltest/analyze.html?d=e6853.ce.akamaiedge-staging.net. Please recognize that this test is not testing the correct SNI in this test, subsequently resulting in a certificate mismatch error. Ignoring the mismatch, you can see we are presenting the full chain in staging and the same will apply once it's deployed to produciton on the 12th.
... View more