One of the biggest issues with working with child actors is that they grow up. That’s especially a problem for shows that can take years to film and get through post-production, leading to delays in renewals and then filming the next season. So, having a child actor on A Knight of the Seven Kingdoms could have been a problem.
Showrunner Ira Parker doesn’t see it as an issue, according to an interview with Variety. The question about Ansell growing up and the issues Stranger Things faced came up.

Egg grows up in the novels by George R.R. Martin
There isn’t that much of a reason to worry about Ansell growing up on A Knight of the Seven Kingdoms. The stories of Dunk and Egg by George R.R. Martin focus a little on Egg growing up. That allows for some time to pass on the series.
There is also a bigger idea Parker has for the series, and it involves time for Ansell to grow up. There is a bit of a joke to focus a few seasons on Egg as a boy and then return after a bit to focus on Egg as a young man. Later on, the show could return to offer some seasons as Egg older and wiser.
"He’ll grow older with the character; he’s supposed to get older. Hopefully, it’s not all based on him having a cute, high voice. We understand how important that is right now, but hopefully he will develop and the characters will develop, and it will still be a lot of fun."
However, even if the show continues in the more traditional way, there’s no need to be concerned with Ansell getting older. Egg is supposed to get older, and that means the actor can as well. At first, the cuteness is the key, but later, we’ll get to see him a little more like a teenager.

There’s plenty to tell on A Knight of the Seven Kingdoms
It turns out that while there are just a handful of novellas out right now, the Dunk and Egg stories will continue for some time. Parker shared that Martin has 12–15 books in mind, and some of the writers on A Knight of the Seven Kingdoms have seen snippets of all of them. This helps them all stay on track with the story.
After all, we’ve seen what happens with the Game of Thrones universe if the writers don’t stay on track. Game of Thrones and House of the Dragon have suffered considerably because of it, so A Knight of the Seven Kingdoms needs to learn from this.
With so many books, though, it will take us through the years. This allows for some exciting stories without worrying about Ansell aging.
A Knight of the Seven Kingdoms airs on Sundays at 10/9c on HBO.
