Or as bad depending on Material and cooling.
Overall I had two (low number, which is good) cases where people were struggling as filament got stuck after a while. Which might a combination of cooler 4010 and lower torque stepper (0.9). In both cases the stepper was not able to push filament forward. As Icarus is using also a 4010 fan and same hotend it would be interesting to get some feedback on reliabilty on PLA and PETG wich I see more critical especially on the HB cooling.
4020 fan is recommended for Hercules, the distance for the airflow is much longer. I've not had any issues with a Sunon Maglev 4020.
It could also be a little low printing temp but unlikely if it happens later in a print. Or too low tension on the BMG lever. Or a glitch in the ribbon connector or thermocouple. But my money is on the fan.