no... P43 is harmans smallest BTU pellet stove unless they still make the P38 which is also 43K BTU's but doesn't have auto Ignition.
Overkill in BTU size only
becomes a problem when dealing with Air conditioning as the cooled air in a small room with an oversized AC will cause that air to blow back to the AC thermostat which will determine that the room is cooled there by shutting down too soon and never getting the humidity out of the room. [ damp/clamy feeling on your skin.]
All an oversized pellet stove will do is melt the occupants
if allowed to be Full throttle when not needed and waste pellets...