You are talking about vertical load changes that can happen anywhere on the circuit not just the turns. These changes do cause the grip levels to change and thus the G loads. Other than changing the the G load constant it has no bearing on weight transfer. Weight transfer, as stated in pounds (lb), is measured at a moment in time. There is no time descriptor in the answer, lb/sec for example. As far as the weight transfer calculation is concerned, the track surface condition is not relevant.
A driver inputs can change the amount of weight transfer. He is look for feedback before formulating the next input. With vertical loads caused by the track surface, the driver has provided no input before the vertical load change and thus does not expect feedback. A driver can only react to these vertical load changes.
I have to think about the FV response to rear vertical load changes, zero roll and chassis stiffness. I'ii get back to you on that.
Brian