Avoiding small gap between two NavmeshCut objects for pathfinding with radius

Maybe somebody (aka Aron it seems :p) has an idea or different approach for me:

For a RTS style game with different unit sizes, i’m using a recast graph, planning to have different navmeshes for different unit sizes.
My goal is, that the units pathfinding avoids each other.
Step 1 was to use navmeshCut objects on each unit. This works fine, except the cut around the unit performing a pathfinding task leads to an undesired detour. I can solve this by temporarily disabeling the navmeshCut (+ forceUpdate). As a sidequestion: is this performant and/or a better way to solve seekers acting as dynamic obstacles?

Now i have the case that when two unit’s meshCutter leave a small gap between them, another unit can still pathfind itself through them. Ideal it would take the searching Units size in account, navigating around the two others.
First thought was to adjust the navmeshCut sizes of other units temporarily by adding the searchers radius to them (and forceUpdating every navmeshCut), but this seems to have a too big performance hit.

So i could try to improve performance (trying to minimize forceUpdates for many units) but maybe i get it wrong in general and should use a completely different approach?