Stephen Amell says that Crisis on Earth-X is so big, The CW will have to change its approach to its annual crossover events moving forward. Next week, The CW’s biggest Arrowverse crossover ever kicks off on Legends of Tomorrow at their regular time. From what’s been seen so far in the trailers, it is a project unlike anything the network has undertaken since launching the Arrow in 2012, which gives Amell’s comments plenty of added weight.

It’s the name of the game, as the first crossover between Arrow and The Flash turned into a ratings winner, and demonstrated what a firm grasp of its DC Comics universe The CW’s then-two productions had. Since then, the Arrowverse has doubled in size, adding both Supergirl and Legends, making the annual gathering of heroes a massive commitment for not only the network, but also all of the actors involved — especially since Crisis reportedly unfolds more like a four-hour movie than as separate interconnected installments focused primarily on a specific show’s cast.

Related: The Flash’s Grant Gustin on How Ralph Dibny Makes Season 4 More Fun

That requires some intense scheduling and as Amell told those taking part in a recent Arrow set visit, the lessons learned from Crisis needs to inspire some changes for the next event. Amell said:

"Not to get too inside baseball here, but they have made it bigger than ever… The crossovers this year took up six full weeks of shooting. I think that in order for us to continue down this path, we as productions, and The CW, as the network, and Warner Bros., as the studio, are going to have to fundamentally re-conceive how we execute these because this sort of broke the schedule mold. I mean it just simply didn't fit.

I think that if we're going to shoot it like a big four-hour movie, we have to board it like a big four-hour movie. We have to prioritize the schedules of the people that are going to be working the most, if that's me, if that's Melissa, if that's Caity Lotz, if that's Grant. It's going to change year over year based off of story. It really is, for the first time, it's an event. It's not a crossover anymore. Call it the crossover if you want. But it's kind of like calling the Super Bowl just a football game. Yeah, sure, they play football, but there's so much other stuff that goes on with it. It's an event."

Amell’s comments offer some insight into how these crossovers are made, and the commitment they require from the cast and crew of these productions. As Amell mentioned, Oliver Queen enjoys a substantial role in Crisis on Earth-X, as does his doppelgänger, presumably. That means actors like Amell and Melissa Benoist were pulling double-duty to make sure both sides of the inter-dimensional conflict were adequately represented. Given that sort of workload in the middle of a season, it’s no wonder Amell would like to see the crossovers blocked out and scheduled differently.

With any luck, the length production on Crisis will pay off. The only downside to the crossover — excuse me, event — finding success will mean the next year’s will have to be that much bigger.

Next:

Crisis on Earth-X begins Monday, @8pm with Supergirl and Arrow. It continues on Tuesday @8pm with The Flash and Legends of Tommorrow.