YMMV, but I am pretty sure that longer reach removes some weight from your hands. Lowering the bars would tend to put it back. Moving the seat forward puts more weight on your hands. Although human bodies are floppy things and not mechanical structures.
I know the following are in conflict: I can feel 6mm difference, but my seat was 1 inch low on PBP 2019 and it didn't really bother me until my knee started complaining on the way back from Brest. Going to take a tape measure the next time I have to take the seat off.