I had a new Winegard antenna installed on my TV tower as a replacement for a 20 year old Winegard antenna (both on rotor). After the installation I noticed they forgot to extend what I call the "wings" on the antenna. Now that I am getting the new digital signals over the air I have become concerned that they may be required to get the best digital signal. I would be interested in what your technical experts have to say about it.
By not unfolding the wing on your UHF director elements your UHF performance will definitely be affected and reduced. The amount of reduction will depend on the UHF channel frequency and the amount of signal strength received at the antenna. If the channel is a local channel and very strong it may not be a problem however your distant channels will suffer. I would suggest that you have the wing unfolded as they should be.