Question:
Has anyone done Fantasmic standby recently, and if so how was your experience?
Background:
My family will be in WDW in June and we’d like to see Fantasmic, but we would not like to pay for a dining package or wait an hour. Basically I would like to show up 30 min before and take whatever seats we can get. Is that even possible?
P.S. There are no LLs, right? It’s just dining package or standby?
Great questions.
We will do standby in early May and can report back. This group advised me recentlly that especially if you are not particularly fussy about seats, lining up 30 minutes early is fine. I too don’t want to do dining package, and there are no LLs. (I just asked all the same questions!) 
If there is a 2nd show it will be less crowded!
Oh ha! I guess my search didn’t pull up the right threads. 
I will be there THIS Saturday night! 
I think there is only one show and I can take pictures of how it fills in. We do have the dining package and may take advantage of accessible seating depending on how my Dad feels about the bench seating.
Following because I want to do the same. Last time, we waited over an hour and honestly didn’t get great seats so I’d rather show up shortly before the show this year.
Sorry, but there are two. They are at 8:30 and 10:00. You can see it twice! 
The dining package seating is only good at the first show, when there are two shows.
If November counts as (somewhat) recent, we went to the second show and it never filled (multiple sections were empty). They didn’t let anyone in standby enter until 30 minutes before. You also get to sit in the middle since there aren’t any dining packages which is nice.
I don’t think I’ve ever arrived more than 30 minutes before though and have always had a seat, so I wouldn’t anticipate any issues. I’ve gotten a seat arriving as it was starting and after it started too, but those seats were either at the far end or in the back section, so I wouldn’t recommend cutting it that close.
I also went in November and we watched it on standby twice. We arrived about 30 mins prior.
I also went last August with the same arrival.
Oh I’m fine if there are two shows! It will take the pressure off our show a little. I would definitely do the second instead of the dining package without kids.
We’re planning Fantasmic standby on 4/26 and I will report back. 
We’re going to ride Slinky as late as possible (so like 8:10pm?) and then book it over there, unless we pop in the day before just to ride Slinky and ToT after dark.
I was at the same November show as @QwertySC and also arrived about 30 mins early. No problem finding seats. Though @QwertySC and I didn’t realize we were at the same show until after it ended so it was a missed Liner meet-up!
The prior year I went in October and same situation … 30 mins early, no issue getting seats.
I am sure I posted about something else and went off in a different direction as I often do!
I saw Fantasmic two nights ago. While I did have the dining package seating, there were still plenty of seats up to about ten minutes before the show. The last two sections on either side were still empty at that time but then started filling up. I would think 30 minutes before should be good depending on crowd level the day you are there!