The first idea I had recently was something to give away the location of chamber when he is in his tp field, some sort of sound when a chamber is in his TP nearby. This would allow teams to be weary when approaching a chamber ready to teleport away, while also incentives a riskier play without a TP available.
Another nerf that don't like as much because he would still be very strong but it would make it difficult to make a team comp around him: Make chamber a duelist removing the slow field from his ult and getting rid of his trip. Replace the trip with some mediocre ability allowing him to entry to make him a duelist such as a temporary wall or a very toned down dash or anything anyone can think of. This one would make him a sub optimal attack agent because he would be forced to entry unless running double duelist which gets rid of the extra slot for a 2nd initiator or controller. It also would likely make him very weak on icebox because sage is typically picked with him and that would leave a team with no flank watch. If anyone has any other ideas leave them below but I think these would work better then ruining his tp ability because I believe he is made to be an op character and they don't want to nerf that