Use the rhizome correctly
Java fern is usually attached to hardscape rather than planted with its rhizome buried. Its leaves create broad surfaces where shrimp can graze and rest.
A mature plant may develop small plantlets on older leaves. Those can be left to grow or removed when they are large enough to handle.
Keep expectations practical
Growth rate varies with light and conditions. Remove damaged leaves gently and avoid exposing shrimp to unverified plant dips or fertilizers.
The plant adds structure but does not replace testing, filtration, or maintenance. Keep enough open space to observe the colony and reach debris.
For your own tank
Leave room around the rhizome and attach it to stable wood or stone. If a leaf develops plantlets, wait until they are sturdy before separating them. Avoid repeatedly moving the fern, because each change delays its adjustment to the aquarium.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.