It looks like there is an undocumented config option for destination so you could probably do something like

mrsk deploy --destination staging

It looks like there could be something weird with the traefik container. There is a MRSK command 

mrsk traefik remove

That could help. See if there are any other relevant commands under

mrsk traefik

that could also help.

Have a try again, it appears that the service was locked up, but it's free again.

I'd say it greatly depends on how you have your applications structured. Will they both access the same database or does the Admin page act like a separate entity and will manage the client facing app through an API? If they are sharing the same database, but completely separate apps, how would the two different types of actors access the application? Would they be differentiated through a subdomain or different routes (URI)? Would you completely separate the two into different clusters or use something like a Procfile to launch both applications on the same cluster and mount them at different endpoints?

So there's a lot of questions here (and some of them rhetorical, but just to get your mind thinking about this stuff). 

Yea, it's going to be a weird transition where iOS (and safari) is going to require two actions.