It's also worth noting that Energy Drain/Siphon only have 30s CD's instead of Aetherflow's prior 60s CD. Meaning 60 seconds per Bahamut phase (30s post level 72)

DWT also noteworthy, gives 2.5s reduced cast time. Meaning instant-cast Tri-Bind (Renamed Outburst) (With Ruination also buffing Outburst)

Devotion is changed and now simply increases party members damage by 5%

Phoenix can only be summoned after Bahamut and lasts for 15 seconds.

This means that Egi's are almost removed from the game. Given that per 30 seconds, you'll be able to get a Bahamut out from DWT. Bahamut lasts 20 seconds, Phoenix then lasts 15 seconds. That's 45 seconds of Demi uptime. So... Basically you just wait long enough to spam out Egi Assault I/II and Enkindle and then get rid of your Egi.

Also, at this point, it might actually end up that you might simply end DWT immediately via Deathflare given that you no longer get bonus damage from it and can get it back again to get a Bahamut so quickly.