It is possible to hide the helmet on the costumes in the armored knights pack and the stealthy rogues pack after purchase? When I preview the costume, the hide helmet setting doesn't work.
No only if you put on a hat to do so in the process that's the only way to hide the helm. I see your point I rather enjoy the costumes without the helm sometimes if there was a icon to just turn off the helm or hat on costumes would be sweet.