most good solid fuel stoves (of pretty much all types and sizes) are well sealed and have an adjustable air intake regulator at the base. Get this right and such a stove (of domestic size) can 'stay in' overnight, provided the fuel is loaded up correctly.
Regulating the flue instead can work OK but if there are any leaks in the stove body you can find smoke gets pushed out of them. Adjusting the flue is both easier (you are managing a much larger gas flow) and more difficult (said gas flow is hot, obviously) than regulating the intake.
Ham's design could be regulated either way but it remains to be seen whether the fuel loading flap will seal well enough that it won't either leak air in, or burp smoke out, depending on whether the intake or the flue are used to regulate the flow.
cheers