We currently have a Steamist generator in our master bathroom.  Our kids like it so much, we are considering splitting the steam line into their shower.  Would we just need to purchase another control?  Are there any downfalls to doing this?  I understand we could not use both rooms at the same time.  Thanks for any insight you can lend.

This method is not recommended and the manufacturers frown upon it and it would likely void any warranties.  Also, steam generators only come with one main operating control.  Typically the main operating control is the thermostat so one room would not operate on thermostat and overheat.  There are many safety issues of which are too many to address in this format.