Bring back "invite" button!

For those who don't know: if you go solo, you can't invite till next depth, and nobody can join you (as if you were playing a boss level). Same goes for kicked players. For others to join you, you have to reach next depth. All by yourself. If you die, you have to use energy to revive. If you're locked in a corner by monsters, its the end for your journey, or the end to your wallet, if you just click "revive" all the time.
This also puts party leaders in an awkward position: if you kick someone, a) kicked lose all heat and b) if they can't progress without party, its leader's fault.

So my suggestion is: bring back "invite" button! In other words: let people join those who went solo.
As for "looping protection" - just don't let people re-join same depth of same gate if they just played there. Make them unable to join same depth for an hour or two. And thats it.

Please don't cripple any further a game that's already crippled.