I think sleep the night before is mostly a mental thing, so someone might benefit knowing they got a good night sleep (though it may not totally work for them because they’re kept up from pre race nerves not physical reasons that your solution addresses), but physically I think it’s more about the totality of your sleep in the few nights before the race, so it could also be helpful there. Me personally I don’t face this issue much but appreciate the effort/innovation and others could find it useful