Well the NginX & Drupal parts are covered by the ESI module and BOA's config, which can use the SSI tags nginx needs. So the main tasks around G are to try it on the STG site, and start to implement/tweak the ESI settings on each part of the page that's relevant...:
- Page 'outer', including user menus
- Blocks and regions - the handful of user-specific blocks can be set up
- Key pages and panels - we'd do these by order of hits, so homepage, user register and the main panels templates for news, blogs and other content types.
- All the other bits - then we're into the 20% of the 80/20 rule, so we can review the other pages and blocks/panes as needed.
Assuming this all goes well we can start to implement it on PROD.
But you're right, there's a lot to do in terms of reviewing pages and content areas/blocks/panes. Luckily the server and interaction is covered by BOA out the box with the ESI module, so we're talking config rather than open heart surgery.
Note also that this proposal (G) also overlaps with (F) in that when we've set each block to be 'Per site', 'Per user', 'Per page' or 'don't cache' combinations, we'll have basically nailed the site structure/"Page 'outer'" piece in the first bullet above. So I'd recommend doing F then G.
Summary updated.
