how much control over the narrative was there though, they did not have a spell component for some reason, apart from that they apparently could do whatever
The first idea a player has not working does not a railroad make
Mamba, that question does not matter. You're right, there first idea failing doesn't make a railroad. But, and this is important,
for some, having to simply fill a blank canvas with the DM's whimsical desires, is railroading. It is the old: Gygax, the DM, makes you search the dungeon, until
he feels that you have explored enough to find the secret door.
apparently they can as long as your sandbox misses one option they think of in a spur of the moment
No offense, and this is where I take offense to many, there aren't that many options to escape a plane. You can create many, especially if you have the adventures exploring a sandbox map. But, if you did the work as DM, you would probably have four or five options for them to get out and double the amounts for them to explore. (This is, of course, if you insist they are trapped there.)
- That rhakshaka that teleports north, south, east, west, constantly selling favors for souls. He might have a way to get out.
- Since we're dealing with the Feywild, those two rivers that flow uphill into the latent volcano. Yeah, there are tunnels underneath that are attached to other things that no one controls. But the turtle dragon, Bligmouth, really really really doesn't like visitors.
- That dryad's tree that's full of empty rum bottles and broken heart carvings. Maybe if you get inside her tree, it's like a dimension inside a dimension. It's there you can get out. But to get in her tree requires her permission (forced, coerced, granted, etc.)
- Apparently Winter Court is still managing to bamph in and out. Maybe an assault or surreptitious encounter can help the group use this to their advantage.
- Keeping with the Feywild theme, those blood oranges that grove from old lady's orchard are said to be imbued with honeybee wings, and honeybee wings are known to hold a bit of teleportation magic. So maybe she knows something? (Or her hive knows something?)
If you are going to eliminate conventional magic options (except for wish), then you, as a DM need to think this through. The PCs are trapped in a Hawaiian style island environment, full of volcanoes, orange groves, sugarcane fields, and one where the Winter Court is just pissed at never having any control. Build four or five more areas, with each area leading to NPCs that can offer ideas on how to get out. Maybe two or three ideas each. Let the players roleplay. Let them explore. And
make sure you know how they can get out. Because if it is just, "When I feel like it," then that is railroading to many players.