Worm castings are an ingredient to consider within a growing medium, not a reason to stop thinking about the rest of the mix. The plant still needs suitable drainage, moisture and root space.
Check the product information and the intended use before adding it. Commercial products can differ, and a recommendation for garden soil is not automatically a recipe for a small indoor pot.
Start with a measured batch
Record the ingredients and proportions when you mix them. If the container later stays wetter than expected, you will know what was changed rather than guessing from the appearance of the surface.
Avoid adding several amendments together for the first time. A small trial batch is easier to assess than repotting an entire collection into a mixture whose behaviour you have not observed.
Keep fertiliser already present in the potting medium in mind when planning additional feeding. More ingredients do not necessarily produce a more suitable root environment. Watch the mix in the actual container, including how water enters and drains. That practical record makes the next batch easier to adjust.
The RHS worm-composting guide describes finished worm compost as a soil conditioner or an ingredient in homemade growing media. That is different from treating it as a complete, universal potting medium.
Related reading: Earthworm Castings: Uses, Application and Limitations.