Not a fan!
The ideal configuration is to mount the regulators forward of carbs, nitrous solenoids, etc. All low-pressure lines from the regulators should only run rearward only without turning forward.
Every fitting, solenoid, and foot of line represents a pressure drop. The flowing pressure at the nozzles will be much lower than at the regulator.
This is further complicated by G-forces, of acceleration, pushing back against the flowing fuel, resulting in even lower pressure under actual operating conditions.
Basic rule of thumb; high-pressure flowing forward, low-pressure flowing rearward.