I bet you it is realSuspension travel is a big problem, most racks are fixed (IFS). So you're talking about driveshaft type travel out of a steering shaft.
Plus power probably isn't good. I've seen it before but it's probably rare for a reason.
Running a rack down on an axle is real common in the mud racing world. Not much suspension movement is needed and it typically weighs less. The fast trucks skim across the pit and the rack gives better control.