Honestly, it’s good to raise this so thanks.I am not trying to be a PITA but in my many years of driving trucks i have seen some bad stuff happen safe loading is big part of the job the weight the car can carry isn't really the issue you are driving with 350 Kg of unsecure load if you have to make an emergency stop you and your passenger will be crushed driving slowly is not going to stop that.
I do agree, and there is certainly some risk. I was 35K miles on the road until 5 years ago and I’ve witnessed some unnecessary consequences of speed x load too. It’s purely down to not over extending our overheads until we can cover the cost from profit. But a van IS the next acquisition before any more major kit. We were looking at some last week.