Board Thread:Questions and Answers/@comment-119.94.13.74-20200506132806/@comment-80.180.26.251-20200507013913

Personally I suggest opening them before the war if you can. Having all items from the Incubus King set there makes one of your later investments in Erosia WAY more profitable. It's possible to get them and still get the best results on every event aside from working on Donovan's chances during the Ardan succession crisis (which you can rectify later during the Return to Stineford section) and the Tak'kan vote during the Erosian crisis (which just gives you a cool piece of equipment), if you managed your investments carefully.

If you can't, still try to do them before the end of chapter 4, or you won't get the Incubus King pin, which SL implied will be important to have (along with the other IK items) in some future update.