I did and unsurpisingly (at least to me) there was hardly any dust trapped in there. I regularly use one of those long lint brushes to keep the duct clean, hoping to avoid any issues and cleaned the vent going to the outside too.
As I said before, the flame continuously goes when required (even if timer not turning), it just doesn't seem to get that hot. Does it sound like that could be a thermostat issue or would replacing the timer (which is pretty expensive $93) solve the issue? Thanks for the replies thus far.