I have no experience with using a RMH but I've boiled plenty of syrup. If you're boiling down more than a gallon or so of sap, you probably don't want to do it inside. The steam is sticky and whoever has to clean the walls and ceiling may not like you for a while.
"Hundreds of years from now it will not matter what my bank account was, the sort of house I lived in or the type of car I drove... But the world may be different because I did something so bafflingly crazy that it becomes a tourist destination"