I think it should handle being compressed like that. Though to be fair I have not tested that particular use case.
If you want the best performance I’d recommend the beta version which uses the burst compiler. In that I can simulate 20000 agents at a reasonable frame rate (though this is without any GameObjects, pathfinding or complex rendering, it is purely the RVO cost).
No, it means I think it will not have the same issue.
However I think for the best behaviour you should use the beta version which improves hard collisions a bit (see https://www.arongranberg.com/astar/download).