Pathfinding with AI On Grid and Off Grid with Rigidbody Forces

I have had great success with simple navagent Unity pathfinding implementations for a FPS I am working on. However, I am building an AI that I would like to code to follow a path and then leap towards the character (or randomly). I would like this leap to be a physics based add-force, and let it take the AI off the grid, meanwhile I would stop the Navagent pathfinding. My thought was to have it check if it is ongrid at that point, if this is false, it could leap randomly, or at the character with Physics. If it is on the grid, it could resume navigation via Unity pathfinding. However, whenever I try to implement this I find the navigation starts acting odd (going to weird points or spazzing out). Additionally I do not know of a way to test if the navagent is on a navmesh. Am I approaching this wrong? Should I look into A* Pathfinding or another 3rd party tool?

Okay I discovered a solution myself (I had the motivation to :') and thought I would post it.

I created a parent grouping object and a two children, one is the physics based AI and the other is the NavMesh agent AI (which I simply have invisible and non colliding). I have the physics based AI try to move towards the navmeshAgent transform.position with physics forces, and issue commands to stop the NavMesh agent when necessary.