I would not automatically bare-root and repot every plant, because that can add root stress and does not address adults moving between nearby pots. Likewise, systemic insecticide is best reserved for a labelled need rather than routine prevention, especially around edible plants, pets, and outdoor pollinator access.

I work on KnowYourPlant, and our fungus-gnat guide explains how to match each control step to the egg, larval, and adult stages: https://knowyourplant.app/blog/posts/fungus-gnats-houseplants/

Keeping a simple weekly count on one sticky card per plant group makes it much easier to tell whether the plan is actually working.