Ha! Chicks can 'poof' down from quite a distance! The jump and flap (though the flapping isn't helpful, just instinctive) and since they're so light and the poofyness of their chicky fuzz seems to disperse the air enough that they just land without trouble!
I wouldn't worry about a few feet... maybe if you're worried enough, set a hay bale below it just in case. I saw some drop off a stack of hay bales one time, we thought we'd get them down once they hatched since we didn't want to disturb the broody's nest before that, but then she hatched when we weren't paying attention (of course we should have KNOWN but... ) so a few jumped before someone could get to them! They just came down like little parachutists!!! NOTE!!! I DO NOT!!! recommend anything that high, (probably 10 or 12 feet!!) and now a nest over 10 feet up would be moved sooner, but it happened and all survived. One of the guys got about half down before they all took the 'plunge', but his climbing up sort of chased a few more to jump! It was horrifying at the time, but in the end, kinda funny.