Can I repot a Boston fern in a coconut liner hanging basket?
While Boston ferns typically prefer to be kept a little pot bound, if it is getting difficult to water, especially if the water doesn't seem to be penetrating the soil well, or if you see roots coming from the pot, then it is probably a good time for repotting. In this case, you would go up a couple inches in diameter or two pot sizes, even if it's in a coconut liner go up in size. However, if your plant looks healthy otherwise and doesn't seem to be having any issues, then simply let it be, though you can add in some more soil if necessary.
Here is an article that you may find helpful: https://www.gardeningknowhow.com/houseplants/hpgen/learn-more-about-repotting-houseplants.htm