I recall asking SBI about the rear clearance and they said it was only to access the air filter and fan, and to only pay attention to the stove pipe to wall specs .
Eric
That’s great that they said that but the installation requirements require 16-18 (sorry I forget) minimum clearance to combustibles to the filter box. It’s one of the very few hard requirements.
I could understand providing recommended maintenance access but this is a required clearance.
I’m in a shop situation with an overhead door so I want to be up to spec.