Heater Rate Issue

Anyone have an idea how to change the variable such that the heater rate is allowed to be less? I installed the Ratroaster by Backwoods Tinkerer and get the following error unless I slowly step up the heater setpoints like in 5C increments. I think the fan works so well and turns on immediately that it takes a bit longer for the heater to start heating up, so hoping there's a variable I can change to allow for a slower heat rate before it shuts down the system. Thanks,