What exactly will be missed by prematurely starting the expansion of The Division 2?

The Division 2 has one expansion to date: Warlords of New York. Starting it might fast forward your character progression and lock you out of specific content/gameplay.

The game itself warns about some non-replayable side missions and trophies which might turn unreachable.

Some players talked about some blueprints which might get unavailable retrospectively... True?

Is there a list of unreachable or non-replayable achievments/content/gameplay which I might miss by prematurely starting to play the expansion? (To possibly check it off one by one.)

I currently believe that nothing will be missed, if you exhaust all story main and side missions until reaching “World Tier 1”. But is that true? (Or is there an earlier/later safe point in the game?)

Can someone confirm that all further “invaded” World Tier X missions can be (re-)launched at a later point?

Short Answer:

No you do not miss any important Content if you skip the base Game. The only thing you miss out on are a few Achievements (i do not know which ones), and of course the Story.

All you need to know:

The Bleprints can be gathered after you played through WLONY. I myself missed some Blueprints before i went to NY and i got them after i finished WLONY by just completing the required Missions in WDC.

Yes, the invaded Missions can be replayed once every Week.

A second Character:

I think if you really want to you can just replay the Base Game Story on a 2nd Character if you feel like you missed out on something. However im not sure how exactly that works so this might not be 100% correct.

• blueprints
  • none are missable
  • you can see a list at the crafting table
  • locked blueprints have a hint where to get
    • most are in the big award pool (e.g. take checkpoint level 3+)
  • some blueprints do not show locked
    • but they are part of the (global) count
    • those are awarded as part of the 100 seasonal levels (season 3&4 and repetitions of those)
  • some “hidden” blueprints are not part of the (global) count if you don’t have them
    • e.g. the conversion of the level 1 Lullaby to a level 40 Sweet Dreams
      • the Lullaby is just an inferior Sweet Dreams part of the ultimate edition or something... nothing to be missed here...
• trophies
  • can be missed
  • a bunch is awarded for completing main missions as part of the normal play-through on story difficulty
    • later replay (on higher difficulties) does not award them
  • upgrading settlements and reaching level 30 yields trophies
    • “level 30 boost” upgrades those, but does not grant the trophies
  • a second walk-through would be required for those trophies
• main missions
  • all main missions can be replayed
    • but story-related cut-scenes do not roll a second time and can be missed
• side missions
  • will be missed entirely
  • can not be replayed
  • those mission locations will often (but not always) be recycled for e.g. (replayable) bounties
  • in-game counters/trackers show those missions as finished
• level 30 boost
  • is a misnomer... should be called “world tier 5 boost”
  • fast-forwards all mission content in Washington, including World Tier 2/3 side missions
  • collects Washington SHD caches
  • unlocks all Washington skills
  • finishes 3 out of 6 specializations
  • awards a base amount of money and (rare) resources
  • does not
    • collect collectibles like art, ECHOs, audio recordings
    • finish quarantine areas