@ChristianMaund: Thank your for your advises.
> May I ask why a Nav link isn’t an option for you?
I think the question is up to me.
Of course you can ask. 
On buildings with bigger ledges nav links make no sense in my opinion, because AI should jump up/down on nearest point to a edge and not searching nearest nav link.
Consider a scenario, on which AI is chasing behind the player and player jump in a build with different height levels (platforms) from platform to platform (also up and down on higher and lower levels). Then you want the AI to go straight to the player, and not searching if some meters to left or right is a nav link. AI should go straight to player and then jump up/down on its way to the player.
But not only chasing a player directly is the case where more dynamic solution as nav links make sense. Also when AI perception triggers like “make noise” or “got damaged” and AI makes a “ai move to” to the “location” where the shot came from or the position the shot is fired (simple AI move to), then AI should on very wide ledges not search foor nearest nav link but go straight to the point it should move to.
If someone have a 2d sidescroller, of course your will have no problem here. But if you move in 3D and have buildings and platforms with ledges of 5-30 meters (big containers, etc) then you have to use navlink on a 30 meter edge every 0,5m or something like that to make it smooth and not look like AI is searching for nav links. And when having a lot of plattforms/heigt-levels you will have really many, many needed nav links in every level on every ledge.
I think about your solution. By reading it once, I have not understand the solution. But I will take my time. 
If anybody else has a good idea to make AI jump onto and off wide ledges of several meter without putting in big bunch on nav links on every ledge in the game, would be still ice to read!
Big thanks to ChristianMaund for his idea.