Given infinite resources and development time, this is what I would do for this expansion specifically;

1. Continue the raid tiers as usual. People complain about engame gearing, but honestly, it's the least egregious part of the endgame to me.
2. 6.1 island sanctuary releases, begin with a small zone that contains your house and a small farming area. Over the patches you get access to cleared up land and expand your farm. Simplistic, but not entirely boring. The house can be decorated like any other housing, and the land can be developed with options for certain plant decorations, farm arrangements, and stuff that can be upgraded with stuff like new fences or barns.
3. 6.11, Ala Mhigo Restoration begins! Ranked crafting returns as we head to Ala Mhigo to tear down imperial structures and rebuild internal infrastructure, to revitalize the city's economy and rehome the displaced refugees. At the end of the restoration, we will have access to a city-state with a marketboard and inn. This will serve as a location in the upcoming main story, with flavor text if you participated in the restoration at the time.
4. 6.11, DWU releases.
5. 6.15, the relic series begins. Starting by expanding deeper into central Thavnair including a new zone, we explore the land for the natural resources that they use in their alchemy to enhance our AF weapons. Most notably, we enhance it with Giantsgall crystal for the first stage. This would be the simplistic entry stage to the relic upgrades, like back in 5.25.
6. 6.2, island sanctuary updates.
7. 6.21, Ala Mhigo restoration updates.
8. 6.21, they introduce a zone in Garlemald's capital to be built up like Doma; proper restoration will be saved for future expansions.
9. 6.25, we get the first zone of our Bozja equivalent; this time located in Corvos! Instead of finding remnant imperial forces there, we find that it's also been reclaimed by nature and other mystical enemies. Relics can be upgraded to their next stage.
10. 6.3, the new deep dungeon releases, based on the ruins of the Bounty.
11. 6.3, island sanctuary updates.
12. 6.31, Ala Mhigo restoration updates.
13. 6.31, Omega Ultimate releases.
14. 6.35, second zone of Corvos releases as well as the next relic upgrade stage.
15. 6.4, island sanctuary updates for the last time.
16. 6.4, the game introduces overworld battle content, first of its kind. Based on the side content you've completed, there are now real-time overworld dungeons and duels that can be found across the zones! Starting with ARR areas, to be expanded to the majority of the other zones in 7.0, you can now participate in 1.0 throwback ventures such as Shposhae and Natalan, and receive the opportunity to face off against enemies like Gilgamesh in solo battles! Scales in level based on each zone's relevant expansion.
17. 6.41, Ala Mhigo restoration updates. An aetheryte is now usable for transport directly into the city.
18. 6.45, third zone of Corvos releases as well as the next relic upgrade stage.
19. 6.5, the game introduces the Beastmaster limited job! Battle and tame overworld enemies to gain access to them as pets that fight in your stead. Based on the pet you have out, your hotbar's abilities change entirely. Instead of using your own spells, you do battle with the pets in a style heavily inspired by Pokemon; localization jokes aplenty.
20. 6.51, Ala Mhigo restoration concludes. The fully functional city is now accessible as a hub with an aetheryte, market, marketboard, inn, and airship landing.
21. 6.51, Garlemald and Shinryu Ultimate releases. Begins with sealing Shinryu while fighting on top of Omega.
22. 6.55, the final update for Corvos and relics release.

Custom deliveries: Ameliance, Vrtra, Jullus
Beast tribes: Matanga, Loporrits, Omicrons
Unlisted updates:
-Belated update to SHB sightseeing log
-Update to EW sightseeing log
-Unreal trials now drop recolored, dyeable forms of their extreme's weapons; purely for glamours
-ARR content gets re-scaled to current jobs' firepower, followed by HW. Following expansions to be rebalanced in 7.0+.
-Future msq unlocks previously inaccessible parts of Eorzea; West Shroud, Coerthas, Abalathia's spine, etc.
-Ocean fishing expanded to new locations

This is what I SPECIFICALLY want, if anyone wants to say this sounds like a terrible plan idgaf