Event Duration: 7-7-2019 21:00 PDT - 7-16-2019 20:59 PDT
Any Opportunity to farm the Training Grounds at 1/2 AP is a great period to pick up some Skill Gems and Ascension Pieces along with an unfocused variety of normal ascension materials. The rewards per AP spent during 1/2 AP are pretty darn good as Masters have a whole slew of "stuff" they can get all at once. The main drawback is simply that it isn't very focused; what drops can vary wildly inbetween sessions.
However, as we have the benefit of Clairvoyance Rank EX, we know that a lucrative lottery event full of Skill Gems, Experience and QP is on the horizon. Thus, Masters are advised to mainly think of the upcoming 2 months and what they need to gather in preparation for the Summer Servants whether that is Experience, QP or Skill Gems/Ascension Pieces.
Appling isn't necessarily a bad idea (one can only eat so many during Nero Fest (ETA Early September) after all), but lottery events are generally more efficient.
It is not advised to keep running Daily Quests while the Summer 2018 Event Rerun is active (ETA 12 July), but it may be useful to level any new Servants early in the event.