I did it without using the gateway for anything else but avoiding the first few CB to get behind the pillars. This was within the first week or two of 5.2 so I hadn't heard of that technique. Once I soul shattered before the hounds came out and kept soul shattering on cd, I had no threat issues with Kan and since he can't CB the pit lord, you never need to gateway anyway so you have more dps uptime. This is something you should be doing even on this current patch.
This is how I did it too. I found it a lot easier to control the felhunters this way over the chain-gateway method.