Nit sure how you mean by realtive to other grids but an alternative to the navmesh is the A-star algorithm byt that requires you to have the grid and its current obstacles stored in some kind of indexable data structure and update it whenever something changes.
They use it in the live training video about turn based project template (and in the project itself)
Not sure if ut us more or less performant than navmesh- probably depends on grid density.