What stands out in Mushroom Fields Island
The map screenshot shows that this is not an isolated dot in an empty ocean. Several climates, coastlines, villages, and ocean routes sit within the wider view. That makes the island more practical for a long world because it can serve as a safe center rather than a place that cuts the player off from wood and progression.
How I would approach this world
I would first decide whether the island should be the permanent base or a protected satellite reached by boat. A port, storage district, or villager-safe project suits the biome well. Before moving everything there, compare the nearest forest, village route, and Nether portal options from the shoreline.
Before settling into the world
Open the seed in Java 1.21.5 and visit the Mushroom Fields boundary. Confirm the island's usable area, the exact shape of the coast, and whatever the original player meant by the hidden feature; the surface map cannot identify an unspecified secret by itself.