haulers break if you increase their speed more than 7 times (more than 350%). Coupled with only a single capacity increase this means you have to have roughly 1 hauler per dps for the majority of the dig if you dont want to have huge pillars of dirt covering the cage. Need to fix the speed bug and give them scalable capacity to keep up with dps increases and pit length
thats before the hauler damage upgrade too which literally produces more dirt than they can possibly carry alone due to the lack of capacity upgrades
overall this basically caps you at around 50dps in the current build