I was thinking frequent fire starts and slow laggy draft. As long as it's not like coak carbon that crunchy and flammable all is well.
I would say in your case yes. You are burning hot so your not getting creosote, but the actual fire produces smoke which has soot. The slow draft at first in temps above 50 is slow and as it lingers it can deposit on the walls of the liner/chimney. That's my thoughts, but I am not an expert either.